SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a10193fc7626c50e00d53ed2e2a302bdfeb85aa9f42e00f418c17612c4900992' 
  AND token = 'Ond5XoIVPGtvQbLjHFZcBH7hDjRol5qZXz+RyKOAjLQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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