But it seems to me that an environment that is toxic for women is also an environment that I would find at least somewhat toxic - not because the crap is hitting me, but because there's a bunch of crap. So what I look for might be useful to you.
I'm older - 55 - and some of what I have is just "hey, this feels like that place that I worked, and it was pretty crummy". But I think there are some specific things you can try to look for.
Look for ego in the interviewing process. If the interviewer (even one of them) is trying to show how smart he/she is, that's a red flag. If one of them can't handle it if you disagree, that's a red flag.
Look for what they say about their culture. Or maybe, look for how they say it. It's fine if they have a ping pong table. At least, it's fine if that's an "oh, by the way". If it's a big part of what they have to say about themselves, that's more of a red flag.
Beer is a bigger red flag. The more their description of their culture sounds like a recruiting pitch for a frat house, the more it's probably toxic to someone who doesn't want to live in a frat house. ("We like to party together after work" is also a red flag.)
I don't know your age. I don't know how much of this is just "Get off my lawn!" But you might find some of it useful.