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 (
    97485, 97486, 97487, 97488, 97489, 97490, 
    97491, 97492, 97493, 97494, 97495, 
    97496, 97497, 97498, 97499, 97500, 
    97501, 97502, 97503, 97504, 97505, 
    97525, 97526, 97527, 97528, 97529, 
    97530, 97531, 97532, 97533, 99068, 
    99069, 99070, 99071, 99072, 99073, 
    99074, 99075, 99076, 99077, 99078, 
    99079, 99080, 99081, 99082, 99083, 
    99084, 99085
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00045

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 (97485,97486,97487,97488,97489,97490,97491,97492,97493,97494,97495,97496,97497,97498,97499,97500,97501,97502,97503,97504,97505,97525,97526,97527,97528,97529,97530,97531,97532,97533,99068,99069,99070,99071,99072,99073,99074,99075,99076,99077,99078,99079,99080,99081,99082,99083,99084,99085)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
97485
97486
97487
97488
97489
97490
97491
97492
97493
97494
97495
97496
97497
97498
97499
97500
97501
97502
97503
97504
97505
97525
97526
97527
97528
97529
97530
97531
97532
97533
99068
99069
99070
99071
99072
99073
99074
99075
99076
99077
99078
99079
99080
99081
99082
99083
99084
99085