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 (
    396008, 395983, 309587, 395989, 414436, 
    414408, 414393, 431514, 396058, 414329, 
    396078, 396044, 431590, 414422, 431659, 
    359772, 309590, 359805, 431542, 309585, 
    396002, 414335, 359762, 414429, 414468, 
    431767, 414459, 359808, 414401, 414360, 
    309561, 431605, 396027, 414415, 431734, 
    359744, 396052, 309550, 392230, 392210, 
    392231, 392229, 359752, 392232, 396018, 
    431506, 392255, 392253, 396074, 392252, 
    392254, 359758, 431615, 309576, 366904, 
    389637, 414316, 414488, 414323, 414443, 
    414507, 395996, 431579, 396037, 359478, 
    415577, 391690, 414326, 309567, 414351, 
    396065, 359747, 431667, 415550, 387078, 
    414342, 381626, 309571, 396013, 359779, 
    414534, 387080, 393018, 387083, 430340, 
    359751, 391691, 414541, 391704, 427476, 
    427477, 414525, 387082, 414322, 415554, 
    372040, 393020, 393026, 381634, 393022
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00562

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "140.18"
    },
    "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": 100,
      "rows_produced_per_join": 100,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "120.18",
        "eval_cost": "20.00",
        "prefix_cost": "140.18",
        "data_read_per_join": "682K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`webmarco`.`cscart_product_descriptions`.`product_id` in (396008,395983,309587,395989,414436,414408,414393,431514,396058,414329,396078,396044,431590,414422,431659,359772,309590,359805,431542,309585,396002,414335,359762,414429,414468,431767,414459,359808,414401,414360,309561,431605,396027,414415,431734,359744,396052,309550,392230,392210,392231,392229,359752,392232,396018,431506,392255,392253,396074,392252,392254,359758,431615,309576,366904,389637,414316,414488,414323,414443,414507,395996,431579,396037,359478,415577,391690,414326,309567,414351,396065,359747,431667,415550,387078,414342,381626,309571,396013,359779,414534,387080,393018,387083,430340,359751,391691,414541,391704,427476,427477,414525,387082,414322,415554,372040,393020,393026,381634,393022)) and (`webmarco`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}