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 (
    96579, 96580, 96581, 96582, 96583, 96584, 
    96585, 96586, 96587, 96588, 96589, 
    96590, 96591, 96592, 96593, 96594, 
    96595, 96596, 96597, 96598, 96599, 
    96600, 96677, 96679, 96684, 96685, 
    96693, 98445, 98682, 99369, 99370, 
    99371, 99372, 99373, 99399, 99400, 
    99401, 99402, 99403, 99507, 99511, 
    99515, 100361, 100362, 100363, 100364, 
    100365, 100366, 100367, 100368, 100369, 
    100370, 100371, 100372, 100373, 100384, 
    100385, 100540, 100541, 100542, 100543, 
    100544, 100545, 100546, 100547, 100548, 
    100549, 100550, 100551, 100552, 100553, 
    100554, 100555, 100556, 100557, 100558, 
    100559, 100560, 100561, 100562, 100563, 
    100564, 100565, 100566, 100567, 100568, 
    100569, 100570, 100571, 100572, 100573, 
    100574, 100575, 100576, 100577, 100578
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00163

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 (96579,96580,96581,96582,96583,96584,96585,96586,96587,96588,96589,96590,96591,96592,96593,96594,96595,96596,96597,96598,96599,96600,96677,96679,96684,96685,96693,98445,98682,99369,99370,99371,99372,99373,99399,99400,99401,99402,99403,99507,99511,99515,100361,100362,100363,100364,100365,100366,100367,100368,100369,100370,100371,100372,100373,100384,100385,100540,100541,100542,100543,100544,100545,100546,100547,100548,100549,100550,100551,100552,100553,100554,100555,100556,100557,100558,100559,100560,100561,100562,100563,100564,100565,100566,100567,100568,100569,100570,100571,100572,100573,100574,100575,100576,100577,100578)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
96579
96580
96581
96582
96583
96584
96585
96586
96587
96588
96589
96590
96591
96592
96593
96594
96595
96596
96597
96598
96599
96600
96677
96679
96684
96685
96693
98445
98682
99369
99370
99371
99372
99373
99399
99400
99401
99402
99403
99507
99511
99515
100361
100362
100363
100364
100365
100366
100367
100368
100369
100370
100371
100372
100373
100384
100385
100540
100541
100542
100543
100544
100545
100546
100547
100548
100549
100550
100551
100552
100553
100554
100555
100556
100557
100558
100559
100560
100561
100562
100563
100564
100565
100566
100567
100568
100569
100570
100571
100572
100573
100574
100575
100576
100577
100578