So OP, you think he's doing cocaine, you know he's doing drugs which you don't like and he's eyeing up women and commenting on them to you despite you saying you don't like it and you're worried if he might be hiding stuff on his phone.
Given the above, he probably is hiding stuff on his phone (probably his drug dealer for one thing), but given the above, why do you care and why are you still with him? The drug use and the comments about women alone should be enough if you don't like either.
There's more people out there and most don't do drugs or content on women in front of their partners.
Fwiw, if my partner wanted to look at my phone, she can. I've nothing to hide. It's not a diary or a confessional, it's a phone. I use it to ring people, look stuff up and send emails and messages. If any of that needs to be hidden from my partner then I shouldn't be doing it (unless it's buying them a present obviously). I ask them who they're messaging or who messages them and vice versa when we're chatting in bed. It's not a big deal.
In a previous relationship a name flashed up on a partner's phone with the first part of a message while they were sleeping in my arms. I moved to silence it so it wouldn't wake then and saw the message fragment. The message fragment was talking about remembering their naked body. You can bet your ass I snooped after that and my partner woke to find me leaving them.