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 (1603, 1605, 1604) 
ORDER BY 
  cscart_images_links.position, 
  cscart_images_links.pair_id

Query time 0.00164

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "read_sorted_file": {
          "filesort": {
            "sort_key": "cscart_images_links.position, cscart_images_links.pair_id",
            "table": {
              "table_name": "cscart_images_links",
              "access_type": "range",
              "possible_keys": ["object_id"],
              "key": "object_id",
              "key_length": "81",
              "used_key_parts": ["object_id", "object_type", "type"],
              "rows": 6,
              "filtered": 100,
              "index_condition": "cscart_images_links.object_type = 'promo' and cscart_images_links.`type` = 'M' and cscart_images_links.object_id in (1603,1605,1604)"
            }
          }
        }
      },
      {
        "table": {
          "table_name": "cscart_images",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "4",
          "used_key_parts": ["image_id"],
          "ref": ["cscart.cscart_images_links.image_id"],
          "rows": 1,
          "filtered": 100
        }
      },
      {
        "table": {
          "table_name": "cscart_common_descriptions",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "108",
          "used_key_parts": ["object_id", "lang_code", "object_holder"],
          "ref": ["cscart.cscart_images.image_id", "const", "const"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "trigcond(cscart_common_descriptions.object_holder = 'images' and cscart_common_descriptions.lang_code = 'en' and trigcond(cscart_images.image_id is not null))"
        }
      }
    ]
  }
}