I am not sure where you want to perform check for the user who confirmed email address. But this is what you need to do.
if (qa_get_logged_in_flags() == QA_USER_FLAGS_EMAIL_CONFIRMED) {
// your code
}
Above condition will check if user email address is confirmed by flag value. Which should be 1 if confirmed.
If you want to cross check if user is logged in (however it is not so required in this case) than you can use core function qa_is_logged_in() within the condition.
Hope this will helps you to what you want to do.