SELECT 
  1 
FROM 
  information_schema.statistics 
WHERE 
  table_schema = DATABASE() 
  AND table_name = 'cscart_cities' 
  AND index_name = 'cs' 
LIMIT 
  1

Query time 0.00062

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "5.21"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "cat",
          "access_type": "index",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "name",
          "used_key_parts": [
            "name"
          ],
          "key_length": "194",
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "using_index": true,
          "cost_info": {
            "read_cost": "0.25",
            "eval_cost": "0.10",
            "prefix_cost": "0.35",
            "data_read_per_join": "224"
          },
          "used_columns": [
            "id"
          ]
        }
      },
      {
        "table": {
          "table_name": "sch",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY",
            "catalog_id"
          ],
          "key": "catalog_id",
          "used_key_parts": [
            "catalog_id",
            "name"
          ],
          "key_length": "202",
          "ref": [
            "mysql.cat.id",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "using_index": true,
          "cost_info": {
            "read_cost": "0.25",
            "eval_cost": "0.10",
            "prefix_cost": "0.70",
            "data_read_per_join": "256"
          },
          "used_columns": [
            "id",
            "catalog_id",
            "name"
          ]
        }
      },
      {
        "table": {
          "table_name": "tbl",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY",
            "schema_id",
            "collation_id"
          ],
          "key": "schema_id",
          "used_key_parts": [
            "schema_id",
            "name"
          ],
          "key_length": "202",
          "ref": [
            "mysql.sch.id",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.25",
            "eval_cost": "0.10",
            "prefix_cost": "1.05",
            "data_read_per_join": "31K"
          },
          "used_columns": [
            "id",
            "schema_id",
            "name",
            "collation_id",
            "hidden"
          ],
          "attached_condition": "((0 <> can_access_table(`mysql`.`sch`.`name`,`mysql`.`tbl`.`name`)) and (`mysql`.`tbl`.`collation_id` is not null))"
        }
      },
      {
        "table": {
          "table_name": "coll",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "id"
          ],
          "key_length": "8",
          "ref": [
            "mysql.tbl.collation_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "using_index": true,
          "cost_info": {
            "read_cost": "0.25",
            "eval_cost": "0.10",
            "prefix_cost": "1.40",
            "data_read_per_join": "232"
          },
          "used_columns": [
            "id"
          ]
        }
      },
      {
        "table": {
          "table_name": "idx",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY",
            "table_id"
          ],
          "key": "table_id",
          "used_key_parts": [
            "table_id",
            "name"
          ],
          "key_length": "202",
          "ref": [
            "mysql.tbl.id",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.25",
            "eval_cost": "0.10",
            "prefix_cost": "1.75",
            "data_read_per_join": "6K"
          },
          "used_columns": [
            "id",
            "table_id",
            "name",
            "hidden",
            "options"
          ],
          "attached_condition": "((`mysql`.`idx`.`name` collate utf8mb3_tolower_ci) = 'cs')"
        }
      },
      {
        "table": {
          "table_name": "icu",
          "access_type": "ref",
          "possible_keys": [
            "index_id",
            "index_id_2",
            "column_id"
          ],
          "key": "index_id_2",
          "used_key_parts": [
            "index_id"
          ],
          "key_length": "8",
          "ref": [
            "mysql.idx.id"
          ],
          "rows_examined_per_scan": 4,
          "rows_produced_per_join": 4,
          "filtered": "100.00",
          "using_index": true,
          "cost_info": {
            "read_cost": "0.25",
            "eval_cost": "0.40",
            "prefix_cost": "2.40",
            "data_read_per_join": "128"
          },
          "used_columns": [
            "index_id",
            "column_id",
            "hidden"
          ],
          "attached_condition": "(0 <> is_visible_dd_object(`mysql`.`tbl`.`hidden`,((0 <> `mysql`.`idx`.`hidden`) or (0 <> `mysql`.`icu`.`hidden`)),`mysql`.`idx`.`options`))"
        }
      },
      {
        "table": {
          "table_name": "col",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "id"
          ],
          "key_length": "8",
          "ref": [
            "mysql.icu.column_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 4,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "1.00",
            "eval_cost": "0.40",
            "prefix_cost": "3.81",
            "data_read_per_join": "25K"
          },
          "used_columns": [
            "id",
            "name"
          ]
        }
      },
      {
        "table": {
          "table_name": "stat",
          "access_type": "eq_ref",
          "possible_keys": [
            "schema_name"
          ],
          "key": "schema_name",
          "used_key_parts": [
            "schema_name",
            "table_name",
            "index_name",
            "column_name"
          ],
          "key_length": "776",
          "ref": [
            "const",
            "const",
            "mysql.idx.name",
            "mysql.col.name"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 4,
          "filtered": "100.00",
          "using_index": true,
          "cost_info": {
            "read_cost": "1.00",
            "eval_cost": "0.40",
            "prefix_cost": "5.21",
            "data_read_per_join": "3K"
          },
          "used_columns": [
            "schema_name",
            "table_name",
            "index_name",
            "column_name"
          ],
          "attached_condition": "<if>(is_not_null_compl(stat), ((`mysql`.`idx`.`name` = `mysql`.`stat`.`index_name`) and (`mysql`.`col`.`name` = `mysql`.`stat`.`column_name`)), true)"
        }
      }
    ]
  }
}