SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44a6d0bfdd568dfc8e491abc8ef2492105c27cad6ff2843e46edd6069124929b' 
  AND token = 'svQteLOrrLw+kX1uH8qrAuYRFd7elKFLD+IgjRmP3j8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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