sin - If somebody is over 60 and does an aveirah for which the punishment is misah biyedei shamayim, what happens?

I was learning today's Tanya (יג תמוז, beginning of אגרת התשובה פרק ד)

I have a question based on the following part:

כשעבר עבירה שחייבים עליה כרת, הי׳ מת ממש קודם חמשים שנה

A violator of a sin punishable by excision would actually die before his fiftieth year.

ובמיתה בידי שמים, מת ממש קודם ששים שנה

In the case of death by divine agency he would actually die before sixty,

כחנניה בן עזור הנביא, בירמיהו

like the prophet Chananiah ben Azur in Jeremiah.

From here we see that כרת is dying before one turns fifty and that מיתה בידי שמים is dying before one turns sixty.

So, my question is what happens if someone does an aveirah for which the punishment is one of these after 50 or 60 (for כרת or מיתה בידי שמים respectively)? Do they die instantaneously?