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 (
    99427, 99428, 99429, 99430, 99431, 99432, 
    99433, 99434, 99435, 99436, 99437, 
    99529, 99530, 99531, 99532, 99533, 
    99534, 99535, 99536, 99537, 99538, 
    99539, 99540, 99541, 99542, 99543, 
    99544, 99545, 99546, 99547, 99548, 
    99549, 99550, 99551, 99552, 99553, 
    99554, 99555, 99556, 99557, 99574, 
    99575, 99576, 100161, 100162, 100163, 
    100164, 100165, 100166, 100167, 100168, 
    101637, 101638, 101669, 101670, 101672, 
    101673, 101674, 101675, 101676, 101677, 
    101688, 101689, 101690, 101691, 101692, 
    101693, 101696, 101697, 101698, 101699, 
    101700, 101701, 101702, 101703, 101704, 
    101705, 101706, 101707, 101708, 101709, 
    101710, 101711, 101712, 101713, 101714, 
    101715, 101716, 101717, 101718, 101719, 
    101720, 101721, 101722, 101723, 101724
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00070

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 (99427,99428,99429,99430,99431,99432,99433,99434,99435,99436,99437,99529,99530,99531,99532,99533,99534,99535,99536,99537,99538,99539,99540,99541,99542,99543,99544,99545,99546,99547,99548,99549,99550,99551,99552,99553,99554,99555,99556,99557,99574,99575,99576,100161,100162,100163,100164,100165,100166,100167,100168,101637,101638,101669,101670,101672,101673,101674,101675,101676,101677,101688,101689,101690,101691,101692,101693,101696,101697,101698,101699,101700,101701,101702,101703,101704,101705,101706,101707,101708,101709,101710,101711,101712,101713,101714,101715,101716,101717,101718,101719,101720,101721,101722,101723,101724)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
99427
99428
99429
99430
99431
99432
99433
99434
99435
99436
99437
99529
99530
99531
99532
99533
99534
99535
99536
99537
99538
99539
99540
99541
99542
99543
99544
99545
99546
99547
99548
99549
99550
99551
99552
99553
99554
99555
99556
99557
99574
99575
99576
100161
100162
100163
100164
100165
100166
100167
100168
101637
101638
101669
101670
101672
101673
101674
101675
101676
101677
101688
101689
101690
101691
101692
101693
101696
101697
101698
101699
101700
101701
101702
101703
101704
101705
101706
101707
101708
101709
101710
101711
101712
101713
101714
101715
101716
101717
101718
101719
101720
101721
101722
101723
101724