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 (
    85710, 88202, 88214, 88686, 88733, 82586, 
    82587, 82608, 82609, 84493, 84559, 
    82630, 83495, 86615, 86616, 86684, 
    86685, 84340, 88177, 88225, 88777, 
    89995, 85674, 87512, 87528, 82599, 
    83362, 88688, 88735, 86637, 86706, 
    84315, 88684, 88685, 88731, 88732, 
    86528, 86529, 86804, 86805, 87511, 
    87527, 88456, 88474, 88490, 83184, 
    83189, 83165
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00107

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.63"
    },
    "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": 48,
      "rows_produced_per_join": 48,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "16.83",
        "eval_cost": "4.80",
        "prefix_cost": "21.63",
        "data_read_per_join": "183K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (85710,88202,88214,88686,88733,82586,82587,82608,82609,84493,84559,82630,83495,86615,86616,86684,86685,84340,88177,88225,88777,89995,85674,87512,87528,82599,83362,88688,88735,86637,86706,84315,88684,88685,88731,88732,86528,86529,86804,86805,87511,87527,88456,88474,88490,83184,83189,83165)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
82586 nuie Arno 500mm Wall Hung 2-Door Vanity & Mid-Edge Basin - Gloss White
82587 nuie Arno 500mm Wall Hung 2-Door Vanity & Minimalist Basin - Gloss White
82599 nuie Arno 600mm Wall Hung 1-Drawer Vanity & Worktop - Gloss White
82608 nuie Arno 600mm Wall Hung 2-Door Vanity & Laminate Top - Gloss White
82609 nuie Arno 600mm Wall Hung 2-Door Vanity & Laminate Top - Gloss White
82630 nuie Arno 800mm Wall Hung 1-Drawer Vanity & Worktop - Gloss White
83165 nuie Athena Floor Standing 2 Door Vanity With Worktop 500mm - Gloss White
83184 nuie Athena Wall Hung Single Drawer Vanity With Worktop 500mm - Anthracite Woodgrain
83189 nuie Athena Wall Hung Single Drawer Vanity With Worktop 500mm - Hacienda Black
83362 nuie Athena Wall Hung Single Drawer Vanity With Worktop 600mm - Gloss White
83495 nuie Athena Wall Hung Single Drawer Vanity With Worktop 800mm - Gloss White
84315 Hudson Reed Fusion Floor Standing WC Unit with Coordinating Top 600mm - Gloss White
84340 Hudson Reed Fusion Wall Hung 1 Door Vanity Unit & Polymarble Basin Compact 400mm - Gloss White
84493 Hudson Reed Fusion Floor Standing WC Unit with Coordinating Top Compact 500mm - Anthracite Woodgrain
84559 Hudson Reed Fusion Floor Standing WC Unit with Coordinating Top Compact 500mm - Hacienda Black
85674 nuie Deco 400mm Wall Hung Tall Unit - Satin White
85710 nuie Deco 400mm Wall Hung Tall Unit - Satin Green
86528 Hudson Reed Juno Compact 440mm Wall Hung Single Door Unit and 1 Tap Hole Basin Left Hand - Autumn Oak
86529 Hudson Reed Juno Compact 440mm Wall Hung Single Door Unit and 1 Tap Hole Basin Right Hand - Autumn Oak
86615 Hudson Reed Juno Compact 440mm Floor Standing Single Door Unit and 1 Tap Hole Basin Left Hand - Graphite Grey
86616 Hudson Reed Juno Compact 440mm Floor Standing Single Door Unit and 1 Tap Hole Basin Right Hand - Graphite Grey
86637 Hudson Reed Juno 600mm Wall Hung 2-Door Vanity & Worktop - Graphite Grey
86684 Hudson Reed Juno Compact 440mm Floor Standing Single Door Unit and 1 Tap Hole Basin Left Hand - Coastal Grey
86685 Hudson Reed Juno Compact 440mm Floor Standing Single Door Unit and 1 Tap Hole Basin Right Hand - Coastal Grey
86706 Hudson Reed Juno 600mm Wall Hung 2-Door Vanity & Worktop - Coastal Grey
86804 Hudson Reed Juno Compact Wall Hung 1 Door Unit & 1 Tap Hole Ceramic Basin Left Hand, 440mm - Metallic Slate
86805 Hudson Reed Juno Compact Wall Hung 1 Door Unit & 1 Tap Hole Ceramic Basin Right Hand, 440mm - Metallic Slate
87511 nuie Athena Wall Hung Tall Unit 1 Door 300mm - Anthracite Woodgrain
87512 nuie Athena Wall Hung Tall Unit 2 Door 300mm - Anthracite Woodgrain
87527 nuie Athena Wall Hung Tall Unit 1 Door 300mm - Hacienda Black
87528 nuie Athena Wall Hung Tall Unit 2 Door 300mm - Hacienda Black
88177 Hudson Reed Juno 550mm WC Unit - Autumn Oak
88202 Hudson Reed Juno 350mm Wall Hung Tall Unit Single Door - Graphite Grey
88214 Hudson Reed Juno 350mm Wall Hung Tall Unit Single Door - Coastal Grey
88225 Hudson Reed Havana Floor Standing Concealed Cistern WC Toilet Unit, 500mm - Metallic Slate
88456 nuie Arno 300mm Tall Unit 1 Door - Solace Oak
88474 nuie Arno 300mm Tall Unit 1 Door - Anthracite
88490 nuie Arno 300mm Tall Unit 1 Door - Charcoal Black
88684 Hudson Reed Fusion Fitted Floor Standing WC Unit 500mm - Anthracite Woodgrain
88685 Hudson Reed Fusion Fitted Floor Standing WC Unit Compact 600mm - Anthracite Woodgrain
88686 Hudson Reed Fusion Fitted Floor Standing WC Unit 600mm - Anthracite Woodgrain
88688 Hudson Reed Fusion Fitted Wall Hung 2 Door Cabinet 500mm - Anthracite Woodgrain
88731 Hudson Reed Fusion Fitted Floor Standing WC Unit 500mm - Hacienda Black
88732 Hudson Reed Fusion Fitted Floor Standing WC Unit Compact 600mm - Hacienda Black
88733 Hudson Reed Fusion Fitted Floor Standing WC Unit 600mm - Hacienda Black
88735 Hudson Reed Fusion Fitted Wall Hung 2 Door Cabinet 500mm - Hacienda Black
88777 Hudson Reed Fusion Fitted Floor Standing WC Unit Compact 500mm - Gloss Grey
89995 nuie Mayford Floor Standing 2 Door Vanity Unit with Square Ceramic Basin 550mm - Gloss White