SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8926279732e3760719a67fcca02c9ac921fca5edd90b8acf9cc9de816f6958d7' 
  AND token = 'ZUlwZ0Hd7gvZABNyCKRVGCz7RqZ26UX8ylMfXDlE6PI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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