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 (
    85036, 85013, 85019, 85025, 85031, 87142, 
    87143, 87144, 87145, 87146, 87147, 
    87285, 88766, 85017, 85023, 85029, 
    85035, 87172, 87173, 87174, 87175, 
    87176, 87177, 87160, 87161, 87162, 
    87163, 87164, 87165, 88672, 88719, 
    89215, 89228, 89241, 87166, 87167, 
    87168, 87169, 87170, 87171, 87136, 
    87137, 87138, 87139, 87140, 87141, 
    87284, 89449
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00117

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 (85036,85013,85019,85025,85031,87142,87143,87144,87145,87146,87147,87285,88766,85017,85023,85029,85035,87172,87173,87174,87175,87176,87177,87160,87161,87162,87163,87164,87165,88672,88719,89215,89228,89241,87166,87167,87168,87169,87170,87171,87136,87137,87138,87139,87140,87141,87284,89449)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
85013 Hudson Reed Solar Floor Standing 2 Drawer Vanity Cabinet 600mm - Pure White
85017 Hudson Reed Solar Wall Hung 2 Drawer Vanity Cabinet 600mm - Pure White
85019 Hudson Reed Solar Floor Standing 2 Drawer Vanity Cabinet 600mm - Cool Grey
85023 Hudson Reed Solar Wall Hung 2 Drawer Vanity Cabinet 600mm - Cool Grey
85025 Hudson Reed Solar Floor Standing 2 Drawer Vanity Cabinet 600mm - Indigo Blue
85029 Hudson Reed Solar Wall Hung 2 Drawer Vanity Cabinet 600mm - Indigo Blue
85031 Hudson Reed Solar 600mm Floor Standing 2-Drawer Unit - Fern Green
85035 Hudson Reed Solar 600mm Wall Hung 2-Drawer Unit - Fern Green
85036 Hudson Reed Solar 800mm Wall Hung 2-Drawer Unit - Fern Green
87136 Old London 600mm Single Bowl Marble Top - 1 Tap Hole - Black
87137 Old London 600mm Single Bowl Marble Top - 1 Tap Hole - White
87138 Old London 600mm Single Bowl Marble Top - 1 Tap Hole - Grey
87139 Old London 600mm Single Bowl Marble Top - 3 Tap Hole - Black
87140 Old London 600mm Single Bowl Marble Top - 3 Tap Hole - White
87141 Old London 600mm Single Bowl Marble Top - 3 Tap Hole - Grey
87142 Old London 800mm Single Bowl Marble Top - 1 Tap Hole - Black
87143 Old London 800mm Single Bowl Marble Top - 1 Tap Hole - White
87144 Old London 800mm Single Bowl Marble Top - 1 Tap Hole - Grey
87145 Old London 800mm Single Bowl Marble Top - 3 Tap Hole - Black
87146 Old London 800mm Single Bowl Marble Top - 3 Tap Hole - White
87147 Old London 800mm Single Bowl Marble Top - 3 Tap Hole - Grey
87160 Old London 750mm Single Bowl Angled Marble Top - 1 Tap Hole - Black
87161 Old London 750mm Single Bowl Angled Marble Top - 1 Tap Hole - White
87162 Old London 750mm Single Bowl Angled Marble Top - 1 Tap Hole - Grey
87163 Old London 750mm Single Bowl Angled Marble Top - 3 Tap Hole - Black
87164 Old London 750mm Single Bowl Angled Marble Top - 3 Tap Hole - White
87165 Old London 750mm Single Bowl Angled Marble Top - 3 Tap Hole - Grey
87166 Old London 1000mm Single Bowl Angled Marble Top - 1 Tap Hole - Black
87167 Old London 1000mm Single Bowl Angled Marble Top - 1 Tap Hole - White
87168 Old London 1000mm Single Bowl Angled Marble Top - 1 Tap Hole - Grey
87169 Old London 1000mm Single Bowl Angled Marble Top - 3 Tap Hole - Black
87170 Old London 1000mm Single Bowl Angled Marble Top - 3 Tap Hole - White
87171 Old London 1000mm Single Bowl Angled Marble Top - 3 Tap Hole - Grey
87172 Old London 1200mm Single Bowl Angled Marble Top - 1 Tap Hole - Black
87173 Old London 1200mm Single Bowl Angled Marble Top - 1 Tap Hole - White
87174 Old London 1200mm Single Bowl Angled Marble Top - 1 Tap Hole - Grey
87175 Old London 1200mm Single Bowl Angled Marble Top - 3 Tap Hole - Black
87176 Old London 1200mm Single Bowl Angled Marble Top - 3 Tap Hole - White
87177 Old London 1200mm Single Bowl Angled Marble Top - 3 Tap Hole - Grey
87284 Old London Components Single Bowl Marble Worktop Top 1 Tap Hole, 600mm - White
87285 Old London Components Single Bowl Marble Worktop Top 1 Tap Hole, 800mm - White
88672 Hudson Reed Fusion Fitted Floor Standing 4 Drawer Lined Unit 300mm - Anthracite Woodgrain
88719 Hudson Reed Fusion Fitted Floor Standing 4 Drawer Lined Unit 300mm - Hacienda Black
88766 Hudson Reed Fusion Fitted Floor Standing 4 Drawer Lined Unit 300mm - Gloss Grey
89215 Hudson Reed Sarenna Wall Hung 2 Drawer Vanity Unit 706mm - Moon White
89228 Hudson Reed Sarenna Wall Hung 2 Drawer Vanity Unit 706mm - Dove Grey
89241 Hudson Reed Sarenna Wall Hung 2 Drawer Vanity Unit 706mm - Mineral Blue
89449 Lunar Components Floor Standing 2 Drawer Unit, 800mm - Satin Anthracite