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 (
    99136, 99137, 99138, 99139, 99140, 99145, 
    99146, 99147, 99148, 99149, 99150, 
    99153, 99154, 99155, 99156, 99157, 
    99158, 99159, 99160, 99161, 99167, 
    99181, 99185, 99186, 99187, 99188, 
    99195, 99196, 99201, 99202, 99205, 
    99210, 99211, 99212, 99213, 99214, 
    99215, 99216, 99217, 99220, 99234, 
    99235, 99236, 99237, 99238, 99240, 
    99241, 99264, 99265, 99266, 99267, 
    99268, 99269, 100386, 100387, 100393, 
    100394, 100434
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00052

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "26.13"
    },
    "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": 58,
      "rows_produced_per_join": 58,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "20.33",
        "eval_cost": "5.80",
        "prefix_cost": "26.13",
        "data_read_per_join": "221K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (99136,99137,99138,99139,99140,99145,99146,99147,99148,99149,99150,99153,99154,99155,99156,99157,99158,99159,99160,99161,99167,99181,99185,99186,99187,99188,99195,99196,99201,99202,99205,99210,99211,99212,99213,99214,99215,99216,99217,99220,99234,99235,99236,99237,99238,99240,99241,99264,99265,99266,99267,99268,99269,100386,100387,100393,100394,100434)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
99136
99137
99138
99139
99140
99145
99146
99147
99148
99149
99150
99153
99154
99155
99156
99157
99158
99159
99160
99161
99167
99181
99185
99186
99187
99188
99195
99196
99201
99202
99205
99210
99211
99212
99213
99214
99215
99216
99217
99220
99234
99235
99236
99237
99238
99240
99241
99264
99265
99266
99267
99268
99269
100386
100387
100393
100394
100434