SELECT 
  cscart_images.*, 
  cscart_images_links.*, 
  cscart_common_descriptions.description AS alt, 
  cscart_images.image_id AS images_image_id 
FROM 
  cscart_images_links 
  LEFT JOIN cscart_images ON cscart_images_links.image_id = cscart_images.image_id 
  LEFT JOIN cscart_common_descriptions ON cscart_common_descriptions.object_id = cscart_images.image_id 
  AND cscart_common_descriptions.object_holder = 'images' 
  AND cscart_common_descriptions.lang_code = 'en' 
WHERE 
  cscart_images_links.object_type = 'promo' 
  AND cscart_images_links.type = 'M' 
  AND cscart_images_links.object_id IN (
    18373, 20817, 17712, 21015, 1311973, 
    1312103
  ) 
ORDER BY 
  cscart_images_links.position, 
  cscart_images_links.pair_id

Query time 0.00240

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "34.81"
    },
    "ordering_operation": {
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "6.00"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_images_links",
            "access_type": "range",
            "possible_keys": [
              "object_id"
            ],
            "key": "object_id",
            "used_key_parts": [
              "object_id",
              "object_type",
              "type"
            ],
            "key_length": "81",
            "rows_examined_per_scan": 6,
            "rows_produced_per_join": 6,
            "filtered": "100.00",
            "index_condition": "((`webmarco`.`cscart_images_links`.`object_type` = 'promo') and (`webmarco`.`cscart_images_links`.`type` = 'M') and (`webmarco`.`cscart_images_links`.`object_id` in (18373,20817,17712,21015,1311973,1312103)))",
            "cost_info": {
              "read_cost": "13.21",
              "eval_cost": "1.20",
              "prefix_cost": "14.41",
              "data_read_per_join": "576"
            },
            "used_columns": [
              "pair_id",
              "object_id",
              "object_type",
              "image_id",
              "detailed_id",
              "type",
              "position"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_images",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "image_id"
            ],
            "key_length": "4",
            "ref": [
              "webmarco.cscart_images_links.image_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 6,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "6.00",
              "eval_cost": "1.20",
              "prefix_cost": "21.61",
              "data_read_per_join": "4K"
            },
            "used_columns": [
              "image_id",
              "image_path",
              "image_x",
              "image_y",
              "is_high_res"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_common_descriptions",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "object_id",
              "lang_code",
              "object_holder"
            ],
            "key_length": "108",
            "ref": [
              "webmarco.cscart_images.image_id",
              "const",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 6,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "6.00",
              "eval_cost": "1.20",
              "prefix_cost": "28.81",
              "data_read_per_join": "3K"
            },
            "used_columns": [
              "object_id",
              "description",
              "lang_code",
              "object_holder"
            ]
          }
        }
      ]
    }
  }
}