SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f463f15bf901acfefaae48663039abfafe1a3faa18ab9a46569588466394a69' 
  AND token = 'ImiyPjDGN8bsxugfSxd2PVXmzcGcQhANh9U/7rM0zaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}