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 (
    90714, 90720, 90713, 90719, 90728, 90729, 
    90717, 90723, 90725, 90727, 90712, 
    90718, 90730, 90731, 90724, 90726, 
    90716, 90722, 89243, 89244, 89253, 
    89254, 90715, 90721, 90048, 90049, 
    90050, 90051, 90052, 90053, 90042, 
    90043, 90044, 90045, 90046, 90047, 
    90058, 90059, 87836, 93834, 93835, 
    93882, 93883, 93884, 93885, 96122, 
    96124, 96125, 96126, 96127, 96131, 
    96155, 96156, 99031, 99367, 99368, 
    100395, 100396, 100415, 100416, 100867, 
    100868, 100869, 100870, 100877, 100878, 
    101654, 101655
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00210

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "30.63"
    },
    "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": 68,
      "rows_produced_per_join": 68,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "23.83",
        "eval_cost": "6.80",
        "prefix_cost": "30.63",
        "data_read_per_join": "259K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (90714,90720,90713,90719,90728,90729,90717,90723,90725,90727,90712,90718,90730,90731,90724,90726,90716,90722,89243,89244,89253,89254,90715,90721,90048,90049,90050,90051,90052,90053,90042,90043,90044,90045,90046,90047,90058,90059,87836,93834,93835,93882,93883,93884,93885,96122,96124,96125,96126,96127,96131,96155,96156,99031,99367,99368,100395,100396,100415,100416,100867,100868,100869,100870,100877,100878,101654,101655)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
87836 nuie Linton Square Single Ended Bath 1500 x 700mm
89243 nuie Shower Baths 1700mm Left Hand Square Shower Bath Set
89244 nuie Shower Baths 1700mm Right Hand Square Shower Bath Set
89253 nuie Shower Baths 1500mm Left Hand Square Shower Bath Set
89254 nuie Shower Baths 1500mm Right Hand Square Shower Bath Set
90042 nuie Shower Baths L-Shape Square Shower Bath Left Hand 1700mm - No Leg Set
90043 nuie Shower Baths L-Shape Square Shower Bath Right Hand 1700mm - No Leg Set
90044 nuie Shower Baths L-Shape Square Shower Bath Left Hand 1500mm - No Leg Set
90045 nuie Shower Baths L-Shape Square Shower Bath Right Hand 1500mm - No Leg Set
90046 nuie Shower Baths L-Shape Square Shower Bath Left Hand 1600mm - No Leg Set
90047 nuie Shower Baths L-Shape Square Shower Bath Right Hand 1600mm - No Leg Set
90048 nuie Shower Baths 1500mm Left Hand Square Shower Bath
90049 nuie Shower Baths 1500mm Right Hand Square Shower Bath
90050 nuie Shower Baths 1600mm Left Hand Square Shower Bath
90051 nuie Shower Baths 1600mm Right Hand Square Shower Bath
90052 nuie Shower Baths 1700mm Left Hand Square Shower Bath
90053 nuie Shower Baths 1700mm Right Hand Square Shower Bath
90058 nuie Shower Baths L-Shape Square Shower Bath Left Hand 1700mm - No Leg Set
90059 nuie Shower Baths L-Shape Square Shower Bath Right Hand 1700mm - No Leg Set
90712 Nuie 1700 Square Bath Panel & Chrome Screen - Left Hand
90713 Nuie 1700 Square Bath Panel & Chrome Screen - Left Hand
90714 Nuie 1700 Square Bath Panel & Chrome Screen - Left Hand
90715 Nuie 1700 Square Bath Panel & Chrome Screen - Left Hand
90716 Nuie 1700 Square Bath Panel & Chrome Screen - Left Hand
90717 Nuie 1700 Square Bath Panel & Chrome Screen - Left Hand
90718 Nuie 1700 Square Bath Panel & Chrome Screen - Right Hand
90719 Nuie 1700 Square Bath Panel & Chrome Screen - Right Hand
90720 Nuie 1700 Square Bath Panel & Chrome Screen - Right Hand
90721 Nuie 1700 Square Bath Panel & Chrome Screen - Right Hand
90722 Nuie 1700 Square Bath Panel & Chrome Screen - Right Hand
90723 Nuie 1700 Square Bath Panel & Chrome Screen - Right Hand
90724 Nuie 1700 Square Bath Panel & Black Screen - Left Hand
90725 Nuie 1700 Square Bath Panel & Black Screen - Left Hand
90726 Nuie 1700 Square Bath Panel & Black Screen - Right Hand
90727 Nuie 1700 Square Bath Panel & Black Screen - Right Hand
90728 Nuie 1700 Square Bath Panel & Black Screen - Left Hand
90729 Nuie 1700 Square Bath Panel & Black Screen - Right Hand
90730 Nuie 1700 Square Bath Panel & B/Brass Screen - Left Hand
90731 Nuie 1700 Square Bath Panel & B/Brass Screen - Right Hand
93834
93835
93882
93883
93884
93885
96122
96124
96125
96126
96127
96131
96155
96156
99031
99367
99368
100395
100396
100415
100416
100867
100868
100869
100870
100877
100878
101654
101655