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 = 'blog' 
  AND cscart_images_links.type = 'M' 
  AND cscart_images_links.object_id IN (50, 48, 49, 42, 47, 46, 45) 
ORDER BY 
  cscart_images_links.position, 
  cscart_images_links.pair_id

Query time 0.00061

JSON explain

{
  "query_block": {
    "select_id": 1,
    "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": 14,
          "filtered": 100,
          "index_condition": "cscart_images_links.object_type = 'blog' and cscart_images_links.`type` = 'M' and cscart_images_links.object_id in (50,48,49,42,47,46,45)"
        }
      }
    },
    "table": {
      "table_name": "cscart_images",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "4",
      "used_key_parts": ["image_id"],
      "ref": ["cscart_purchase_fl_com.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_purchase_fl_com.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))"
    }
  }
}

Result

image_id image_path image_x image_y is_high_res pair_id object_id object_type detailed_id type position alt images_image_id
9183 Panda_Alright_close.jpg 3648 3648 N 1102 42 blog 0 M 0 9183
9186 Bangkok_TERMINAL_21_04_genm-16.jpg 1000 667 N 1105 45 blog 0 M 0 9186
9187 Panda_Smoking_panda_close_piil-fw.jpg 3648 3648 N 1106 46 blog 0 M 0 9187
9188 Panda_Behind_the_scene_close_r7sa-pu.jpg 3648 3648 N 1107 47 blog 0 M 0 9188
9189 Panda_Dango_close_jx87-mb.jpg 3648 3648 N 1108 48 blog 0 M 0 9189
9190 Panda_Come_Together_close_h42i-yb.jpg 3648 3648 N 1109 49 blog 0 M 0 9190
9191 sakosshu-blog01-01s_vrz5-6e.jpg 1000 1000 N 1110 50 blog 0 M 0 9191