SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c66f0147ca30225d3c7f483dc7db37b92e1561a2fb1bbb17ed7ce999fd7df28d' 
  AND token = 'lNYmhBbMNAMAfBqedFBzb6OjOJFW/DWUOjrnh8Ijb24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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