SELECT 
  DISTINCT cscart_companies.city, 
  cscart_companies.country 
FROM 
  cscart_companies 
WHERE 
  cscart_companies.status = 'A' 
  AND cscart_companies.city != '' 
ORDER BY 
  cscart_companies.city ASC

Query time 0.00144

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "202.44"
    },
    "ordering_operation": {
      "using_filesort": false,
      "duplicates_removal": {
        "using_temporary_table": true,
        "using_filesort": true,
        "cost_info": {
          "sort_cost": "57.24"
        },
        "table": {
          "table_name": "cscart_companies",
          "access_type": "ALL",
          "rows_examined_per_scan": 636,
          "rows_produced_per_join": 57,
          "filtered": "9.00",
          "cost_info": {
            "read_cost": "133.75",
            "eval_cost": "11.45",
            "prefix_cost": "145.20",
            "data_read_per_join": "545K"
          },
          "used_columns": [
            "company_id",
            "status",
            "city",
            "country"
          ],
          "attached_condition": "((`webmarco`.`cscart_companies`.`status` = 'A') and (`webmarco`.`cscart_companies`.`city` <> ''))"
        }
      }
    }
  }
}