SELECT 
  COUNT(*) 
FROM 
  cscart_ec_hb_facilities 
  LEFT JOIN cscart_ec_hb_facilities_desc ON cscart_ec_hb_facilities_desc.facility_id = cscart_ec_hb_facilities.facility_id 
  AND cscart_ec_hb_facilities_desc.lang_code = 'en' 
WHERE 
  1

Query time 0.00066

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "10.42"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_ec_hb_facilities",
          "access_type": "index",
          "key": "PRIMARY",
          "used_key_parts": [
            "facility_id"
          ],
          "key_length": "4",
          "rows_examined_per_scan": 6,
          "rows_produced_per_join": 6,
          "filtered": "100.00",
          "using_index": true,
          "cost_info": {
            "read_cost": "2.02",
            "eval_cost": "1.20",
            "prefix_cost": "3.22",
            "data_read_per_join": "96"
          },
          "used_columns": [
            "facility_id"
          ]
        }
      },
      {
        "table": {
          "table_name": "cscart_ec_hb_facilities_desc",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "facility_id",
            "lang_code"
          ],
          "key_length": "10",
          "ref": [
            "atulecarter_atul_demo1.cscart_ec_hb_facilities.facility_id",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 6,
          "filtered": "100.00",
          "using_index": true,
          "cost_info": {
            "read_cost": "6.00",
            "eval_cost": "1.20",
            "prefix_cost": "10.42",
            "data_read_per_join": "4K"
          },
          "used_columns": [
            "facility_id",
            "lang_code"
          ],
          "attached_condition": "<if>(is_not_null_compl(cscart_ec_hb_facilities_desc), (`atulecarter_atul_demo1`.`cscart_ec_hb_facilities_desc`.`facility_id` = `atulecarter_atul_demo1`.`cscart_ec_hb_facilities`.`facility_id`), true)"
        }
      }
    ]
  }
}