SELECT 
  product_descriptions.product_id, 
  product_descriptions.short_description, 
  IF(
    product_descriptions.short_description = '' 
    OR product_descriptions.short_description IS NULL, 
    product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  product_descriptions 
WHERE 
  product_descriptions.product_id IN (
    385234, 385743, 385759, 386519, 386543, 
    387062, 387067, 387083, 387085, 387090, 
    387093, 387867, 389162, 390517, 391802, 
    393120, 393149, 393683, 393694, 394420, 
    394433, 394436, 394441, 394471
  ) 
  AND product_descriptions.lang_code = 'en'

Query time 0.00127

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "19.81"
    },
    "table": {
      "table_name": "product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "11",
      "rows_examined_per_scan": 24,
      "rows_produced_per_join": 24,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "17.41",
        "eval_cost": "2.40",
        "prefix_cost": "19.81",
        "data_read_per_join": "122K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`goimagine`.`product_descriptions`.`product_id` in (385234,385743,385759,386519,386543,387062,387067,387083,387085,387090,387093,387867,389162,390517,391802,393120,393149,393683,393694,394420,394433,394436,394441,394471)) and (`goimagine`.`product_descriptions`.`lang_code` = 'en'))"
    }
  }
}