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 (
    91048, 91049, 91050, 84547, 84548, 84551, 
    84552, 84613, 84614, 84617, 84618, 
    84335, 84336, 84490, 84491, 84556, 
    84557, 85109, 84321, 89491, 89492, 
    89499, 89500, 89507, 89508, 89515, 
    89516, 83254, 83256, 83261, 83263, 
    90562, 90563, 90568, 90569, 90574, 
    90575, 86141, 86164, 86649, 86718, 
    85072, 85074, 85158, 85160, 85204, 
    85206, 85250, 85252, 84499, 84565, 
    83030, 83032, 83587, 83589, 90866, 
    90868, 90945, 90947, 85112, 85114, 
    84489, 84555, 91090, 91091, 91094, 
    91095, 91097, 91098, 91099, 91176, 
    91177, 91180, 91181, 91183, 91184, 
    91185, 91231, 91232, 91235, 91236, 
    91238, 91239, 91240, 83268, 83270, 
    90544, 90545, 84520, 84521, 84545, 
    84586, 84587, 84611, 86619, 86621
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00204

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 (91048,91049,91050,84547,84548,84551,84552,84613,84614,84617,84618,84335,84336,84490,84491,84556,84557,85109,84321,89491,89492,89499,89500,89507,89508,89515,89516,83254,83256,83261,83263,90562,90563,90568,90569,90574,90575,86141,86164,86649,86718,85072,85074,85158,85160,85204,85206,85250,85252,84499,84565,83030,83032,83587,83589,90866,90868,90945,90947,85112,85114,84489,84555,91090,91091,91094,91095,91097,91098,91099,91176,91177,91180,91181,91183,91184,91185,91231,91232,91235,91236,91238,91239,91240,83268,83270,90544,90545,84520,84521,84545,84586,84587,84611,86619,86621)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}