Generally speaking, do ALL comps have to be recent, as in within the last three to five years? The comps I wanted to use in my query are from 2001 and 1983 respectively.
I'd rather just not use comps at all, but from what I've seen, most agents want 'em. So many rules, so little time.
Generally, yeah. I mean four or six years or whatever, if it fits really well, and isn't super well known, no one will really care but pushing 20 and 35... that's a problem.
It's not about a rule, but about that the agent wants to see that you're aware of the current market and your genre and category.
If your comps are both from decades ago, it might signal you don't read any current stuff (this is a thing that happens), and hence, write in the same style as was popular 35 years ago, but isn't now, or write stuff that's outmoded in other ways, or write stuff that's really, really, really been covered, but you don't know it's not a new thought or new angle, because you (not you you, the general, theoretical you), haven't read much since back when.
It'd be like if someone's comps were both really old sci-fi -- an agent might worry that the writer hasn't kept up with what's been written since in sci-fi and is just retreading stuff people are well over.
Kind of the same reason your comps should never be blockbusters or classics or even usually so popular they were made into movies or tv shows -- it doesn't indicate you're familiar enough with the market, for one, because you might just read the big blockbuster books, and those are also almost always older by the time they've hit, so you're pushing into what's likely a saturated market. The other problem is it sounds pompous -- this is like I, Robot crossed with LotR -- just makes an agent roll his or her eyes at the hubris.