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 (
    88056, 88057, 88058, 87998, 88000, 88037, 
    90329, 90330, 90331, 90333, 90334, 
    90337, 90338, 90339, 90340, 90341, 
    90342, 90345, 90346, 90347, 90348, 
    87881, 88031, 87948
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00079

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "12.97"
    },
    "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": 24,
      "rows_produced_per_join": 24,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "10.57",
        "eval_cost": "2.40",
        "prefix_cost": "12.97",
        "data_read_per_join": "91K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (88056,88057,88058,87998,88000,88037,90329,90330,90331,90333,90334,90337,90338,90339,90340,90341,90342,90345,90346,90347,90348,87881,88031,87948)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
87881 nuie Mayford Square Ceramic 1 Tap Hole Basin 550mm
87948 nuie Provost Short Projection Cistern
87998 nuie Provost 420mm Small Basin 1 Tap Hole
88000 nuie Provost Medium 520mm Basin 1 Tap Hole
88031 nuie Legend Large Basin 2 Tap Hole
88037 Old London Richmond 515mm Cloakroom Basin
88056 Old London Richmond 560mm Basin 2 Tap Hole
88057 Old London Richmond 560mm Basin 1 Tap Hole
88058 Old London Richmond 560mm 3 Tap Hole Basin
90329 nuie Ceramics Accessories Universal Access Cistern & Matt Black Square Flush Plate
90330 nuie Ceramics Accessories Universal Access Cistern & Brushed Brass Square Flush Plate
90331 nuie Ceramics Accessories Concealed Cistern & Square Push Button - Gunmetal
90333 nuie Ceramics Accessories Universal Access Cistern & Matt Black Traditional Flush Plate
90334 nuie Ceramics Accessories Universal Access Cistern & Brushed Brass Traditional Flush Plate
90337 nuie Ceramics Accessories Universal Access Cistern & Matt Black Square Flush Plate
90338 nuie Ceramics Accessories Universal Access Cistern & Black Square Flush Plate
90339 nuie Ceramics Accessories Universal Access Cistern & Brushed Brass Square Flush Plate
90340 nuie Ceramics Accessories Universal Access Cistern & Brushed Brass Flush Plate
90341 nuie Ceramics Accessories Concealed Cistern & Square Push Button - Gunmetal
90342 nuie Ceramics Accessories Dual Flush Cistern & Square Push Button - Gunmetal
90345 nuie Ceramics Accessories Universal Access Cistern & Matt Black Traditional Flush Plate
90346 nuie Ceramics Accessories Universal Access Cistern & Matt Black Traditional Flush Plate
90347 nuie Ceramics Accessories Universal Access Cistern & Brushed Brass Traditional Flush Plate
90348 nuie Ceramics Accessories Universal Access Cistern & Brushed Brass Traditional Flush Plate