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 (
    83007, 83290, 83292, 83297, 83299, 84806, 
    84807, 84824, 84825, 84836, 84837, 
    91096
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00054

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "5.41"
    },
    "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": 12,
      "rows_produced_per_join": 12,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "4.21",
        "eval_cost": "1.20",
        "prefix_cost": "5.41",
        "data_read_per_join": "45K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (83007,83290,83292,83297,83299,84806,84807,84824,84825,84836,84837,91096)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
83007 nuie Arno 600mm Floor Standing 2-Drawer Vanity & Curved Basin - Charcoal Black
83290 nuie Athena Floor Standing 2 Drawer Vanity With Thin-Edge 1 Tap Hole Ceramic Basin 600mm - Anthracite Woodgrain
83292 nuie Athena Floor Standing 2 Drawer Vanity With Curved 1 Tap Hole Ceramic Basin 600mm - Anthracite Woodgrain
83297 nuie Athena Floor Standing 2 Drawer Vanity With Thin-Edge 1 Tap Hole Ceramic Basin 600mm - Hacienda Black
83299 nuie Athena Floor Standing 2 Drawer Vanity With Curved 1 Tap Hole Ceramic Basin 600mm - Hacienda Black
84806 nuie Classique Floor Standing 2 Door Vanity Basin Unit & 1 Tap Hole Fireclay Basin, 600mm - Satin Anthracite
84807 nuie Classique Floor Standing 2 Door Vanity Basin Unit & 3 Tap Hole Fireclay Basin, 600mm - Satin Anthracite
84824 nuie Classique Floor Standing 2 Door Vanity Basin Unit & 1 Tap Hole Fireclay Basin, 600mm - Satin Grey
84825 nuie Classique Floor Standing 2 Door Vanity Basin Unit & 3 Tap Hole Fireclay Basin, 600mm - Satin Grey
84836 nuie Classique Floor Standing 2 Door Vanity Basin Unit & 1 Tap Hole Fireclay Basin, 600mm - Satin Green
84837 nuie Classique Floor Standing 2 Door Vanity Basin Unit & 3 Tap Hole Fireclay Basin, 600mm - Satin Green
91096 nuie Classique Floor Standing 2 Door Unit & 0 Tap Hole Fireclay Basin, 600mm - Satin Anthracite