SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c2bba4834e5bdffabc72b672fe62193762674578b250d84d5d722b46dfdf0ae' 
  AND token = 'p1sfMRUlNIsvlsqvJRj4Ulfv9RPwWP2bGtjX4N7sLxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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