Where Are All The Erotic Mature Women?

Having recently ended a three-year relationship, I really wanted to spice up my sex life. I don't know what it is, but lately I've had this fantasy of having a fling with an erotic mature lady. Any guys in their 20s looking for older women to hook up with may be sharing my frustration. It seems impossible to find a decent-looking woman in her 40s who is up for casual sex. After checking out a couple sex dating sites, I've had little to no luck and I'm starting to think that maybe they simply don't exist.