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 (
    344273, 344818, 344830, 344862, 345580, 
    345599, 346144, 346904, 347464, 347482, 
    347494, 348241, 348791, 349541, 349556, 
    349572, 350107, 350857, 350863, 351442, 
    352743, 355401, 355439, 356137
  ) 
  AND product_descriptions.lang_code = 'en'

Query time 0.00129

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "19.82"
    },
    "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": "17.42",
        "eval_cost": "2.40",
        "prefix_cost": "19.82",
        "data_read_per_join": "122K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`goimagine`.`product_descriptions`.`product_id` in (344273,344818,344830,344862,345580,345599,346144,346904,347464,347482,347494,348241,348791,349541,349556,349572,350107,350857,350863,351442,352743,355401,355439,356137)) and (`goimagine`.`product_descriptions`.`lang_code` = 'en'))"
    }
  }
}