Nope, it doesn't. It's unavoidable, even in those of us who are activists, and requires no intent. Here, let me show you...
You and a woman both apply for the same job, for which there are two slots. You have equally good resumes. You're equally good interviewers. We'll assume you're the same race, similar educations, socioeconomically similar, etc. Only difference is your sex. You have no idea a woman is applying, so you obviously can't intend to be sexist against her, can you.
You're both hired. But the boss decides to pay her a third less than he pays you.
Or, if the boss doesn't think she's pretty enough, he just doesn't hire her at all.
You may not be the one making the call, but you are complicit, because you are living the benefit of your sex. You're participating in a system that we all know is stacked a certain way.
What do you do about that? Well, in the moment, what could you? Nothing you can do, since it's happening even when you don't know it's happening. And hey, you need to eat too. It's not like it's reasonable to expect you to just decide not to make a living. It's not really up to you if your employer is quietly sexist and that gives you an edge you didn't know you had.
What you can do is, in the grander scheme of things, participate in things that dismantle the culture that inherently values men more than women.
And yes, an example of that would be not letting **** slide when you find out that your buddy thinks raping women is funny.