SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13cc5fb960b9088ba65a21c3d973ff18fec5b9414b3708e1d460a915291be893' 
  AND token = 'QcJgKSNSS0Yozy+QW35b6RQfkLdzWxoZN6PrYXGpAHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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