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 (
    87367, 87366, 87365, 87364, 87358, 87380, 
    87357, 87379, 82541, 82539, 82540, 
    82538, 89565, 89564, 92587, 92588, 
    92589, 93942, 93943, 93944, 93945, 
    93946, 93947, 95063, 95064, 95065, 
    95069, 95070, 95071, 95072
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00060

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "13.52"
    },
    "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": 30,
      "rows_produced_per_join": 30,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "10.52",
        "eval_cost": "3.00",
        "prefix_cost": "13.52",
        "data_read_per_join": "114K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (87367,87366,87365,87364,87358,87380,87357,87379,82541,82539,82540,82538,89565,89564,92587,92588,92589,93942,93943,93944,93945,93946,93947,95063,95064,95065,95069,95070,95071,95072)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
82538 nuie Pacific 1200 x 800mm Offset Quadrant Enclosure - 6mm Glass - Polished Chrome
82539 nuie Pacific 1200 x 800mm Offset Quadrant Enclosure - 6mm Glass - Polished Chrome
82540 nuie Pacific 1200 x 900mm Offset Quadrant Enclosure - 6mm Glass - Polished Chrome
82541 nuie Pacific 1200 x 900mm Offset Quadrant Enclosure - 6mm Glass - Polished Chrome
87357 Hudson Reed Apex 1000 x 800mm Offset Quadrant Enclosure - 8mm Glass - Polished Chrome
87358 Hudson Reed Apex 1000 x 800mm Offset Quadrant Enclosure - 8mm Glass - Polished Chrome
87364 Hudson Reed Apex 1200 x 800mm Offset Quadrant Enclosure - 8mm Glass - Polished Chrome
87365 Hudson Reed Apex 1200 x 800mm Offset Quadrant Enclosure - 8mm Glass - Polished Chrome
87366 Hudson Reed Apex 1200 x 900mm Offset Quadrant Enclosure - 8mm Glass - Polished Chrome
87367 Hudson Reed Apex 1200 x 900mm Offset Quadrant Enclosure - 8mm Glass - Polished Chrome
87379 Hudson Reed Apex 900 x 800mm Offset Quadrant Enclosure - 8mm Glass - Polished Chrome
87380 Hudson Reed Apex 900 x 800mm Offset Quadrant Enclosure - 8mm Glass - Polished Chrome
89564 nuie Rene 1000 x 800mm Offset Quadrant - 6mm Glass - Satin Chrome
89565 nuie Rene 1000 x 800mm Offset Quadrant - 6mm Glass - Matt Black
92587
92588
92589
93942
93943
93944
93945
93946
93947
95063
95064
95065
95069
95070
95071
95072