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 (
    91280, 91281, 89497, 89498, 89505, 89506, 
    89513, 89514, 89521, 89522, 91162, 
    91163, 91166, 91167, 91169, 91170, 
    91171, 89203, 89216, 89229, 86481, 
    86483, 86757, 86759, 82614, 82616, 
    83417, 83419, 85072, 85074
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00080

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 (91280,91281,89497,89498,89505,89506,89513,89514,89521,89522,91162,91163,91166,91167,91169,91170,91171,89203,89216,89229,86481,86483,86757,86759,82614,82616,83417,83419,85072,85074)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
82614 nuie Arno 1200mm Wall Hung 4-Drawer Vanity & Double Basin - Gloss White
82616 nuie Arno 1200mm Wall Hung 4-Drawer Vanity & Double Basin - Gloss White
83417 nuie Athena Wall Hung 4 Drawer Vanity With Twin Polymarble Basin 1200mm - Gloss White
83419 nuie Athena Wall Hung 4 Drawer Vanity With Twin Ceramic Basin 1200mm - Gloss White
85072 Hudson Reed Fluted 1200mm Wall Hung 2-Drawer Vanity and Double Basin - Satin Anthracite
85074 Hudson Reed Fluted 1200mm Wall Hung 2-Drawer Vanity and Double Basin - Satin Anthracite
86481 Hudson Reed Juno 1200mm Wall Hung 2-Drawer Vanity & Double Basin - Autumn Oak
86483 Hudson Reed Juno 1200mm Wall Hung 2-Drawer Vanity & Double Basin - Autumn Oak
86757 Hudson Reed Juno Wall Hung 2 Drawer Vanity Basin Unit & Double Polymarble Basin, 1200mm - Metallic Slate
86759 Hudson Reed Juno Wall Hung 2 Drawer Vanity Basin Unit & Double Ceramic Basin, 1200mm - Metallic Slate
89203 Hudson Reed Sarenna Wall Hung 2 Drawer Vanity Unit with Polymarble Basin 700mm - Moon White
89216 Hudson Reed Sarenna Wall Hung 2 Drawer Vanity Unit with Polymarble Basin 700mm - Dove Grey
89229 Hudson Reed Sarenna Wall Hung 2 Drawer Vanity Unit with Polymarble Basin 700mm - Mineral Blue
89497 Hudson Reed Solar Wall Hung 2 Drawer Vanity Unit with Polymarble Basin 800mm - Pure White
89498 Hudson Reed Solar Wall Hung 2 Drawer Vanity Unit with Ceramic Basin 800mm - Pure White
89505 Hudson Reed Solar Wall Hung 2 Drawer Vanity Unit with Polymarble Basin 800mm - Cool Grey
89506 Hudson Reed Solar Wall Hung 2 Drawer Vanity Unit with Ceramic Basin 800mm - Cool Grey
89513 Hudson Reed Solar Wall Hung 2 Drawer Vanity Unit with Polymarble Basin 800mm - Indigo Blue
89514 Hudson Reed Solar Wall Hung 2 Drawer Vanity Unit with Ceramic Basin 800mm - Indigo Blue
89521 Hudson Reed Solar 800mm Wall Hung 2-Drawer Unit and Polymarble 1 Tap Hole Basin - Fern Green
89522 Hudson Reed Solar 800mm Wall Hung 2-Drawer Unit and Ceramic 1 Tap Hole Basin - Fern Green
91162 nuie Classique Wall Hung 1 Drawer Unit & 1 Tap Hole Marble Top with Oval Basin, 800mm - Satin White/Black
91163 nuie Classique Wall Hung 1 Drawer Unit & 3 Tap Hole Marble Top with Oval Basin, 800mm - Satin White/Black
91166 nuie Classique Wall Hung 1 Drawer Unit & 1 Tap Hole Marble Top with Oval Basin, 800mm - Satin White/Grey
91167 nuie Classique Wall Hung 1 Drawer Unit & 3 Tap Hole Marble Top with Oval Basin, 800mm - Satin White/Grey
91169 nuie Classique Wall Hung 1 Drawer Unit & 1 Tap Hole Marble Top with Oval Basin, 800mm - Satin White/White
91170 nuie Classique Wall Hung 1 Drawer Unit & 3 Tap Hole Marble Top with Oval Basin, 800mm - Satin White/White
91171 nuie Classique Wall Hung 1 Drawer Unit & 1 Tap Hole Marble Top with Square Basin, 800mm - Satin White/White
91280 nuie Classique Wall Hung 1 Drawer Unit & 3 Tap Hole Marble Top with Oval Basin, 800mm - Satin Green/White
91281 nuie Classique Wall Hung 1 Drawer Unit & 1 Tap Hole Marble Top with Square Basin, 800mm - Satin Green/White