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 (
    82549, 92001, 91885, 91886, 91887, 92329, 
    92330, 92331, 92332, 92000, 92346, 
    91901, 91902, 91903, 92345, 92347, 
    92348, 82551, 92342, 91897, 91898, 
    91899, 92341, 92343, 92344, 88925, 
    88926, 88927, 91470, 91884, 91900, 
    90844, 82430, 82431, 82433, 91896, 
    90272, 86076, 86079, 86080, 90794, 
    90271, 90795, 86077, 86078, 93868, 
    93869, 93870, 93871, 94381, 95557, 
    95944, 96778, 96779, 96780, 96791, 
    96839, 96840, 98192, 98193, 98194, 
    98195, 98196, 98197, 98198, 98199, 
    98208, 98209, 98210, 98211, 98212, 
    98213, 98214, 98215, 98216, 98217, 
    98218, 98219, 98220, 98221, 98222, 
    98223, 98322, 98323, 98563, 98564, 
    98565, 98566, 98567, 98568, 98569, 
    99519, 99520, 99521, 99522, 99523
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00091

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 (82549,92001,91885,91886,91887,92329,92330,92331,92332,92000,92346,91901,91902,91903,92345,92347,92348,82551,92342,91897,91898,91899,92341,92343,92344,88925,88926,88927,91470,91884,91900,90844,82430,82431,82433,91896,90272,86076,86079,86080,90794,90271,90795,86077,86078,93868,93869,93870,93871,94381,95557,95944,96778,96779,96780,96791,96839,96840,98192,98193,98194,98195,98196,98197,98198,98199,98208,98209,98210,98211,98212,98213,98214,98215,98216,98217,98218,98219,98220,98221,98222,98223,98322,98323,98563,98564,98565,98566,98567,98568,98569,99519,99520,99521,99522,99523)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
82430 nuie Enclosure Hook For Frameless Enclosures - Chrome
82431 nuie Enclosure Hook For Framed Enclosures - Chrome
82433 nuie Enclosure Hook For Frameless Enclosures - Smoked Black
82549 Glass Part for D Shaped Enclosure - 6mm Glass
82551 Rail for D Shaped Enclosure - Polished Chrome
86076 nuie Pacific Square Handle - Chrome
86077 nuie Ella Rounded Handle - Chrome
86078 nuie Ella Square Handle - Chrome
86079 nuie Pacific Square Handle - Black
86080 nuie Pacific Single Handle SQ/ - 145mm Centres - Chrome
88925 nuie 1850mm Profile Extension Kit - Chrome
88926 nuie 1850mm Profile Extension Kit - Matt Black
88927 Hudson Reed 1900mm Profile Extension Kit - Polished Chrome
90271 nuie Wetroom Wall Channel 1850mm - Brushed Brass
90272 Return Screen L Profile Kit 1850mm Black - Brushed Brass
90794 Hudson Reed Apex Handle - Chrome
90795 Hudson Reed Apex Handle - Chrome
90844 nuie Pacific Enclosure Screw Cover Kit Chrome, 1850mm - Chrome
91470 nuie Pacific Enclosure Profile Extension Kit, 1850mm - Brushed Brass
91884 BC Designs Victrion 3 Tier Shower Tidy - Chrome
91885 BC Designs Victrion 3 Tier Shower Tidy - Copper
91886 BC Designs Victrion 3 Tier Shower Tidy - Gold
91887 BC Designs Victrion 3 Tier Shower Tidy - Nickel
91896 BC Designs Victrion Corner Shower Basket - Chrome
91897 BC Designs Victrion Corner Shower Basket - Copper
91898 BC Designs Victrion Corner Shower Basket - Gold
91899 BC Designs Victrion Corner Shower Basket - Nickel
91900 BC Designs Victrion Double Corner Shower Basket - Chrome
91901 BC Designs Victrion Double Corner Shower Basket - Copper
91902 BC Designs Victrion Double Corner Shower Basket - Gold
91903 BC Designs Victrion Double Corner Shower Basket - Nickel
92000 BC Designs Victrion Arch Shower Ring 1036mm x 642mm x 374mm - Chrome
92001 BC Designs Victrion Oval Shower Ring 1094mm x 685mm x 374mm - Chrome
92329 BC Designs Victrion Shower Tidy - Brushed Chrome
92330 BC Designs Victrion Shower Tidy - Brushed Copper
92331 BC Designs Victrion Shower Tidy - Brushed Gold
92332 BC Designs Victrion Shower Tidy - Brushed Nickel
92341 BC Designs Victrion Corner Shower Basket - Brushed Chrome
92342 BC Designs Victrion Corner Shower Basket - Brushed Copper
92343 BC Designs Victrion Corner Shower Basket - Brushed Gold
92344 BC Designs Victrion Corner Shower Basket - Brushed Nickel
92345 BC Designs Victrion Double Corner Shower Basket - Brushed Chrome
92346 BC Designs Victrion Double Corner Shower Basket - Brushed Copper
92347 BC Designs Victrion Double Corner Shower Basket - Brushed Gold
92348 BC Designs Victrion Double Corner Shower Basket - Brushed Nickel
93868
93869
93870
93871
94381
95557
95944
96778
96779
96780
96791
96839
96840
98192
98193
98194
98195
98196
98197
98198
98199
98208
98209
98210
98211
98212
98213
98214
98215
98216
98217
98218
98219
98220
98221
98222
98223
98322
98323
98563
98564
98565
98566
98567
98568
98569
99519
99520
99521
99522
99523