SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '' 
    OR cscart_product_descriptions.short_description IS NULL, 
    cscart_product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    91905, 91906, 91907, 91908, 91909, 91910, 
    91911, 84268, 89735, 91904, 89435, 
    82417, 86852, 91921, 91922, 91923, 
    91924, 91925, 91926, 91927, 91929, 
    91930, 91931, 91932, 91933, 91934, 
    91935, 89433, 89434, 89441, 82399, 
    86848, 82414, 86855, 84265, 89432, 
    89731, 89439, 82396, 86851, 89440, 
    82416, 86853, 89431, 84263, 84267, 
    83088, 89124, 89128, 89160, 89551, 
    82343, 91290, 84264, 91913, 91914, 
    91915, 91916, 91917, 91918, 91919, 
    82332, 86814, 86844, 89101, 89729, 
    89734, 91286, 82415, 86854, 90093, 
    90103, 90112, 89438, 82398, 86849, 
    89730, 91293, 82340, 82341, 82346, 
    86389, 86391, 89430, 83115, 83125, 
    83134, 89123, 89127, 89159, 89550, 
    83087, 89437, 91289, 84262, 84266
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00226

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "43.24"
    },
    "table": {
      "table_name": "cscart_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": 96,
      "rows_produced_per_join": 96,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "33.64",
        "eval_cost": "9.60",
        "prefix_cost": "43.24",
        "data_read_per_join": "366K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (91905,91906,91907,91908,91909,91910,91911,84268,89735,91904,89435,82417,86852,91921,91922,91923,91924,91925,91926,91927,91929,91930,91931,91932,91933,91934,91935,89433,89434,89441,82399,86848,82414,86855,84265,89432,89731,89439,82396,86851,89440,82416,86853,89431,84263,84267,83088,89124,89128,89160,89551,82343,91290,84264,91913,91914,91915,91916,91917,91918,91919,82332,86814,86844,89101,89729,89734,91286,82415,86854,90093,90103,90112,89438,82398,86849,89730,91293,82340,82341,82346,86389,86391,89430,83115,83125,83134,89123,89127,89159,89550,83087,89437,91289,84262,84266)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}