SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bcdef32c7374c9bf2da9eee62bdcdf08578a357fe142721a71191c08a6f1042' 
  AND token = 'ylJFOpIQkQLztAUpzndghWokLPcffJ9vHoIPqywcgWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}