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 (
    91061, 88063, 91063, 91062, 91057, 91060, 
    91055, 91058, 91056, 91059, 84848, 
    84912, 87976, 87967, 84910, 87982, 
    87977, 88089, 87968, 88039, 91064, 
    88016, 93151, 93152, 93153, 93155, 
    93157, 93796, 94810, 94825, 95312, 
    95313, 95737, 95755, 95765, 95787, 
    95820, 98230, 98231, 98232, 98324, 
    98326, 98502, 99137, 99138, 99146, 
    99147, 99155, 99186, 99188, 99195, 
    99217, 99241, 99267, 100393, 100394
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00128

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "25.23"
    },
    "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": 56,
      "rows_produced_per_join": 56,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "19.63",
        "eval_cost": "5.60",
        "prefix_cost": "25.23",
        "data_read_per_join": "213K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (91061,88063,91063,91062,91057,91060,91055,91058,91056,91059,84848,84912,87976,87967,84910,87982,87977,88089,87968,88039,91064,88016,93151,93152,93153,93155,93157,93796,94810,94825,95312,95313,95737,95755,95765,95787,95820,98230,98231,98232,98324,98326,98502,99137,99138,99146,99147,99155,99186,99188,99195,99217,99241,99267,100393,100394)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
84848 Hudson Reed Maya Wall Hung Pan & Seat
84910 Hudson Reed Arlo Wall Hung Pan & Seat
84912 Hudson Reed Luna Wall Hung Pan & Seat
87967 nuie Freya Wall Hung Pan & Soft Close Seat
87968 nuie Freya Wall Hung Rimless Toilet Pan & Soft Close Seat - White
87976 nuie Ava Wall Hung Pan & Soft Close Seat
87977 nuie Ava Wall Hung Toilet Pan & Soft Close Seat - White
87982 nuie Ava Wall Hung Pan & Soft Close Seat
88016 nuie Melbourne Wall Hung Pan
88039 nuie Carlton Wall Hung Pan - White
88063 Hudson Reed Grace Rimless Wall Hung Pan & Seat
88089 nuie Provost Wall Hung Pan
91055 Arlo W/H Pan SC Seat & Conc Cistern
91056 Ava W/H Pan SC Seat & Conc Cistern
91057 Ava W/H Pan SC Seat & Conc Cistern
91058 Ava W/H Pan SC Seat & Conc Cistern
91059 Freya W/H Pan SC Seat & Conc Cistern
91060 Freya W/H Pan SC Seat & Conc Cistern
91061 Grace W/H Pan SC Seat & Conc Cistern
91062 Luna W/H Pan SC Seat & Conc Cistern
91063 Maya W/H Pan SC Seat & Conc Cistern
91064 Melbourne W/H Pan & SC Seat
93151
93152
93153
93155
93157
93796
94810
94825
95312
95313
95737
95755
95765
95787
95820
98230
98231
98232
98324
98326
98502
99137
99138
99146
99147
99155
99186
99188
99195
99217
99241
99267
100393
100394