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 (
    97796, 97797, 97798, 98052, 98053, 98149, 
    98150, 98153, 98156, 98762, 98851, 
    98852, 98853, 98854, 98855, 98856, 
    98857, 98858, 99133, 99141, 99142, 
    99151, 99152, 99169, 99170, 99248, 
    99257, 99262, 99322, 99323, 99404, 
    99405, 99406, 99407, 99408, 99409, 
    99410, 99411, 100143, 100392, 100433, 
    100436, 100437, 100677, 100678, 100679, 
    100680, 100681, 100682, 100683, 100684, 
    100685, 100686, 100687, 100688, 100689, 
    100690, 100691, 100692, 100693, 100694, 
    100695, 101011, 101012, 101013, 101014, 
    101015, 101016, 101017, 101018, 101019, 
    101020, 101021, 101625, 101684, 101685, 
    101686, 101687, 101694, 101695, 101963
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00160

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "36.49"
    },
    "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": 81,
      "rows_produced_per_join": 81,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "28.39",
        "eval_cost": "8.10",
        "prefix_cost": "36.49",
        "data_read_per_join": "308K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (97796,97797,97798,98052,98053,98149,98150,98153,98156,98762,98851,98852,98853,98854,98855,98856,98857,98858,99133,99141,99142,99151,99152,99169,99170,99248,99257,99262,99322,99323,99404,99405,99406,99407,99408,99409,99410,99411,100143,100392,100433,100436,100437,100677,100678,100679,100680,100681,100682,100683,100684,100685,100686,100687,100688,100689,100690,100691,100692,100693,100694,100695,101011,101012,101013,101014,101015,101016,101017,101018,101019,101020,101021,101625,101684,101685,101686,101687,101694,101695,101963)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
97796
97797
97798
98052
98053
98149
98150
98153
98156
98762
98851
98852
98853
98854
98855
98856
98857
98858
99133
99141
99142
99151
99152
99169
99170
99248
99257
99262
99322
99323
99404
99405
99406
99407
99408
99409
99410
99411
100143
100392
100433
100436
100437
100677
100678
100679
100680
100681
100682
100683
100684
100685
100686
100687
100688
100689
100690
100691
100692
100693
100694
100695
101011
101012
101013
101014
101015
101016
101017
101018
101019
101020
101021
101625
101684
101685
101686
101687
101694
101695
101963