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 (
    82951, 82952, 82827, 82828, 82900, 82901, 
    82973, 82974, 83190, 83195, 87405, 
    83235, 84342, 88780, 84881, 84896, 
    88977, 88994, 82849, 82922, 82995, 
    83479, 83487, 86626
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00071

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "10.82"
    },
    "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": "8.42",
        "eval_cost": "2.40",
        "prefix_cost": "10.82",
        "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 (82951,82952,82827,82828,82900,82901,82973,82974,83190,83195,87405,83235,84342,88780,84881,84896,88977,88994,82849,82922,82995,83479,83487,86626)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
82827 nuie Arno 600mm Wall Hung 2-Door Vanity & Laminate Top - Solace Oak
82828 nuie Arno 600mm Wall Hung 2-Door Vanity & Laminate Top - Solace Oak
82849 nuie Arno 800mm Wall Hung 1-Drawer Vanity & Worktop - Solace Oak
82900 nuie Arno 600mm Wall Hung 2-Door Vanity & Laminate Top - Anthracite
82901 nuie Arno 600mm Wall Hung 2-Door Vanity & Laminate Top - Anthracite
82922 nuie Arno 800mm Wall Hung 1-Drawer Vanity & Worktop - Anthracite
82951 nuie Arno 500mm Wall Hung 2-Door Vanity & Mid-Edge Basin - Charcoal Black
82952 nuie Arno 500mm Wall Hung 2-Door Vanity & Minimalist Basin - Charcoal Black
82973 nuie Arno 600mm Wall Hung 2-Door Vanity & Laminate Top - Charcoal Black
82974 nuie Arno 600mm Wall Hung 2-Door Vanity & Laminate Top - Charcoal Black
82995 nuie Arno 800mm Wall Hung 1-Drawer Vanity & Worktop - Charcoal Black
83190 nuie Athena Wall Hung Single Drawer Vanity With Mid-Edge 1 Tap Hole Ceramic Basin 500mm - Gloss White
83195 nuie Athena Wall Hung Single Drawer Vanity With Minimalist 1 Tap Hole Ceramic Basin 500mm - Gloss White
83235 nuie Athena Wall Hung 2 Drawer Vanity With Worktop 500mm - Gloss White
83479 nuie Athena Wall Hung Single Drawer Vanity With Worktop 800mm - Anthracite Woodgrain
83487 nuie Athena Wall Hung Single Drawer Vanity With Worktop 800mm - Hacienda Black
84342 Hudson Reed Fusion Wall Hung 1 Door Vanity Unit & Polymarble Basin 400mm - Gloss White
84881 nuie Core Wall Hung 2 Door Vanity Basin Unit & Ceramic Basin, 500mm - Satin Anthracite
84896 nuie Core Wall Hung 2 Door Vanity Basin Unit & Ceramic Basin, 500mm - Satin Green
86626 Hudson Reed Juno 600mm Wall Hung Single Drawer Vanity & Worktop - Graphite Grey
87405 nuie Merit Wall Hung Slimline Single Door Vanity and Ceramic Basin 500mm - Gloss Grey
88780 Hudson Reed Fusion Fitted Floor Standing WC Unit 600mm - Gloss Grey
88977 nuie Parade Wall Hung 2 Door Tall Unit, 356mm - Satin Anthracite
88994 nuie Parade Wall Hung 2 Door Tall Unit, 356mm - Satin Green