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 (
    91667, 91669, 91670, 91671, 91672, 91673, 
    91674, 91675, 91676, 91677, 91699, 
    91648, 91658, 91668, 91772, 91771, 
    91770, 83923, 83930, 83927, 91765, 
    83934, 91766, 83919, 83937, 91769, 
    83936, 91768, 83935, 91767, 83918, 
    83914, 83917, 83920, 83922, 83926, 
    83928, 83929, 91836, 83931, 83932, 
    83916, 83925, 83913, 83921, 83933, 
    83915, 83924
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00100

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 (91667,91669,91670,91671,91672,91673,91674,91675,91676,91677,91699,91648,91658,91668,91772,91771,91770,83923,83930,83927,91765,83934,91766,83919,83937,91769,83936,91768,83935,91767,83918,83914,83917,83920,83922,83926,83928,83929,91836,83931,83932,83916,83925,83913,83921,83933,83915,83924)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}