SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f18b73afae081cb50e3011470410d81608d242aa5c563fc51008e960e7c0caa8' 
  AND token = 'QRiY3Xpvxb1j8GMt8JPV9gaXofyl74k4g8cYqNkJXvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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