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 (
    97368, 97369, 97370, 97371, 97372, 97373, 
    97374, 97375, 97376, 97377, 97378, 
    97379, 97380, 97381, 97382, 97383, 
    97384, 97385, 97386, 97387, 97388, 
    97389, 97390, 97391, 97392, 97393, 
    97394, 97395, 97396, 97397, 97398, 
    97399, 97400, 97401, 97402, 97403, 
    97404, 97405, 97406, 97407, 97408, 
    97409, 97410, 97411, 97412, 97413, 
    97414, 97415
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00102

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.63"
    },
    "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": 48,
      "rows_produced_per_join": 48,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "16.83",
        "eval_cost": "4.80",
        "prefix_cost": "21.63",
        "data_read_per_join": "183K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (97368,97369,97370,97371,97372,97373,97374,97375,97376,97377,97378,97379,97380,97381,97382,97383,97384,97385,97386,97387,97388,97389,97390,97391,97392,97393,97394,97395,97396,97397,97398,97399,97400,97401,97402,97403,97404,97405,97406,97407,97408,97409,97410,97411,97412,97413,97414,97415)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
97368
97369
97370
97371
97372
97373
97374
97375
97376
97377
97378
97379
97380
97381
97382
97383
97384
97385
97386
97387
97388
97389
97390
97391
97392
97393
97394
97395
97396
97397
97398
97399
97400
97401
97402
97403
97404
97405
97406
97407
97408
97409
97410
97411
97412
97413
97414
97415