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 (
    394196, 431190, 430574, 431092, 431106, 
    431147, 430849, 431162, 431128, 431099, 
    431132, 431202, 430637, 430639, 431096, 
    431168, 431141, 431153, 431137, 431155, 
    431033, 431130, 430911, 430640, 431134, 
    431125, 431154, 431090, 431146, 431065, 
    431067, 431187, 431048, 431094, 430697, 
    430767, 431050, 431104, 430745, 431124, 
    431117, 431191, 431157, 431160, 430681, 
    431116, 430743, 430850, 430908, 431084, 
    431107, 430998, 431026, 430655, 430744, 
    431100, 431115, 430915, 430916, 430636, 
    430924, 431195, 430747, 430803, 431176, 
    431203, 430748, 431204, 431133, 430648, 
    431196, 430823, 431158, 431199, 431122, 
    430903, 430848, 431139, 430831, 431150, 
    430665, 430696, 431145, 431102, 430771, 
    430907, 430649, 430646, 430647, 430912, 
    430935, 430638, 430766, 431097, 431151, 
    430821, 430824, 431359, 430857, 431201
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00274

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "140.18"
    },
    "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": 100,
      "rows_produced_per_join": 100,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "120.18",
        "eval_cost": "20.00",
        "prefix_cost": "140.18",
        "data_read_per_join": "682K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`webmarco`.`cscart_product_descriptions`.`product_id` in (394196,431190,430574,431092,431106,431147,430849,431162,431128,431099,431132,431202,430637,430639,431096,431168,431141,431153,431137,431155,431033,431130,430911,430640,431134,431125,431154,431090,431146,431065,431067,431187,431048,431094,430697,430767,431050,431104,430745,431124,431117,431191,431157,431160,430681,431116,430743,430850,430908,431084,431107,430998,431026,430655,430744,431100,431115,430915,430916,430636,430924,431195,430747,430803,431176,431203,430748,431204,431133,430648,431196,430823,431158,431199,431122,430903,430848,431139,430831,431150,430665,430696,431145,431102,430771,430907,430649,430646,430647,430912,430935,430638,430766,431097,431151,430821,430824,431359,430857,431201)) and (`webmarco`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
394196
430574
430636
430637
430638
430639
430640
430646
430647
430648
430649
430655
430665
430681
430696
430697
430743
430744
430745
430747
430748
430766
430767
430771
430803
430821
430823
430824
430831
430848
430849
430850
430857
430903
430907
430908
430911
430912
430915
430916
430924
430935
430998
431026
431033
431048
431050
431065
431067
431084
431090
431092
431094
431096
431097
431099
431100
431102
431104
431106
431107
431115
431116
431117
431122
431124
431125
431128
431130
431132
431133
431134
431137
431139
431141
431145
431146
431147
431150
431151
431153
431154
431155
431157
431158
431160
431162
431168
431176
431187
431190
431191
431195
431196
431199
431201
431202
431203
431204
431359