SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47c36baeacf733ae0913ee9eaf63947026db46ad6d5bbd0ab86f9b1d1fa350c4' 
  AND token = 'ewhXQxArycOcUgf6t+wW6TyB3udGQWJXlGtHkoAAvto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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