be past your sell-by date idiom
UK年龄太老（sell-by date 本意是“最迟销售期限”。如果说某人过了这个期限，则表示某人太老，不再有用，也不再为人所用）
If someone is past their sell-by date, that person is not wanted or considered useful any more because they are too old.
There's plenty of time to have a baby. I'm not past my sell-by date yet. 还有足够的时间生孩子。我还没有过“保质期”。