SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83846a401751cf8a0c4d597cba8f1a9dd42e96d6539c4afe0820ec930df21602' 
  AND token = '65RZHHOBFsAE+OhzUhrh3lt21L8Uh/TuxgBAhGfYWb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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