SELECT 
  q_product_descriptions.product_id, 
  q_product_descriptions.short_description, 
  IF(
    q_product_descriptions.short_description = '', 
    q_product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  q_product_descriptions 
WHERE 
  q_product_descriptions.product_id IN (
    379, 380, 381, 382, 383, 384, 385, 386, 
    387, 388, 389, 390, 391, 392, 393, 394
  ) 
  AND q_product_descriptions.lang_code = 'en'

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "38.41"
    },
    "table": {
      "table_name": "q_product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 16,
      "rows_produced_per_join": 16,
      "filtered": "100.00",
      "index_condition": "((`portal`.`q_product_descriptions`.`product_id` in (379,380,381,382,383,384,385,386,387,388,389,390,391,392,393,394)) and (`portal`.`q_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "35.21",
        "eval_cost": "3.20",
        "prefix_cost": "38.41",
        "data_read_per_join": "61K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ]
    }
  }
}

Result

product_id short_description full_description
379
380
381
382
383
384 <p>Dolce & Gabbana launched The One for Men in 2008 as the fragrance intended to become a masculine classics. In 2015, The One for Men Eau de Parfum appears as an enhanced, denser version of the scent. The elegant top notes of coriander, basil and grapefruit are leading to the heart where there is a warm blend of ginger, orange blossom and cardamom. Tobacco, sensual amber and cedar leave their mark at the base of the perfume.</p>
385
386
387 <ul><li>After presenting more than successful fragrance for women,</li><li> The One, Dolce&Gabbana house launched a fragrance for men named The One for Men at the begining of March 2008.</li></ul>
388
389
390
391
392
393
394