My wallet on MEW is compromised. Someone stole all of my tokens from there. I think they hacked my desktop computer.
Now i expect to receive new tokens on this address and is too late to change with new address.
Is there any chance to change my private key, or to lock them wih password or any 2fa
WTF man, I'm sorry to hear that but I don't think that you can change for private keys on MEW. Are you sure that you have been hacked? Lots of phishing sites specially on MEW that's why I bookmarked it, but if your desktop computer has been hacked better backup everything and do a clean install. There are really a lot of unscrupulous individuals out there, taking advantage of everything specially in crypto's. This is a hard lessons for you to swallow but I guess you can't do anything and all the hardwork you have done getting all this tokens or even tokens you have invested have been stolen from you. Let's this to a lessons for us as well. Just bookmark MEW and don't click any links specially in your email.