Hah! I love the question. It's hilarious.
Cruising is GAY slang for looking for a hook-up for quick sex. Sort of standing around eyeballing another guy, trying to look sexy and hot to seduce him. I've franking never heard it used in a hetersexual context, like men "cruising" women. No. The use of the word probably has its origins in the US from at least the late 60s, or early 70s on forward. It's frankly a little out of date now, but was BIG in the 1970s-1980s (I know, I'm 59 and was very young in those days). Men would hang out at gay bars, gay bathhouses, parks, gay porn bookstores and so on and "cruise", meaning they'd be looking for quick, no-commitment sex hook ups with another guy. Nothing else. The best book every written about the gay culture of the 1970s was Larry Kramer's 1978 "Faggots", which I know has been translated at least into one other language, German ("Schwuchteln" it's called in the German translation). There's actually a 1980 movie filmed and set in New York City, staring AL Pacino, called "Cruising" about a police detective investigating the murder of gay men in the City at the time, and going undercover. It's not about heterosexuals. Not in the least.