SELECT 
  product_descriptions.product_id, 
  product_descriptions.short_description, 
  IF(
    product_descriptions.short_description = '' 
    OR product_descriptions.short_description IS NULL, 
    product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  product_descriptions 
WHERE 
  product_descriptions.product_id IN (
    380465, 380470, 380472, 380473, 380476, 
    380508, 381231, 381232, 381248, 381259, 
    381262, 381790, 381809, 381825, 381827, 
    381832, 381834, 382560, 382585, 383096, 
    383141, 383151, 383154, 383157
  ) 
  AND product_descriptions.lang_code = 'en'

Query time 0.00249

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "19.95"
    },
    "table": {
      "table_name": "product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "11",
      "rows_examined_per_scan": 24,
      "rows_produced_per_join": 24,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "17.55",
        "eval_cost": "2.40",
        "prefix_cost": "19.95",
        "data_read_per_join": "122K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`goimagine`.`product_descriptions`.`product_id` in (380465,380470,380472,380473,380476,380508,381231,381232,381248,381259,381262,381790,381809,381825,381827,381832,381834,382560,382585,383096,383141,383151,383154,383157)) and (`goimagine`.`product_descriptions`.`lang_code` = 'en'))"
    }
  }
}