SELECT 
  * 
FROM 
  cscart_bm_containers as c 
  LEFT JOIN cscart_bm_grids as g ON g.container_id = c.container_id 
WHERE 
  1 
  AND g.container_id IN (504, 515, 502, 501) 
ORDER BY 
  g.order, 
  g.parent_id, 
  g.grid_id ASC

Query time 0.00086

JSON explain

{
  "query_block": {
    "select_id": 1,
    "ordering_operation": {
      "using_filesort": true,
      "nested_loop": [
        {
          "table": {
            "table_name": "g",
            "access_type": "range",
            "possible_keys": [
              "container_id"
            ],
            "key": "container_id",
            "used_key_parts": [
              "container_id"
            ],
            "key_length": "3",
            "rows": 15,
            "filtered": 100,
            "index_condition": "((`_testcscart`.`g`.`container_id` in (504,515,502,501)) and (`_testcscart`.`g`.`container_id` is not null))"
          }
        },
        {
          "table": {
            "table_name": "c",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "container_id"
            ],
            "key_length": "3",
            "ref": [
              "_testcscart.g.container_id"
            ],
            "rows": 1,
            "filtered": 100
          }
        }
      ]
    }
  }
}