Those queries are simple select queries, there really is no reason for them to take that long at all. The USER_ID field is the primary key in those tables so they should be fast. I'd say there is a bit more going on than they are saying.

If you can at least get access to phpmyadmin, then what you can do is run that exact query and put an EXPLAIN at the front and then post it here. That will show if it's using the index or not. So what you'd do is run it like this:

SQL Query
EXPLAIN SELECT t2.USER_TIME_OFFSET,t2.USER_TOPIC_VIEW_TYPE,t2.USER_TIME_FORMAT, t1.USER_ID, t1.USER_DISPLAY_NAME, t1.USER_PASSWORD, t1.USER_SESSION_ID, t1.USER_MEMBERSHIP_LEVEL, t1.USER_IS_BANNED,t1.USER_RULES_ACCEPTED, t1.USER_IS_UNDERAGE, t2.USER_TOTAL_PM, t2.USER_STYLE, t2.USER_HIDE_LEFT_COLUMN,t2.USER_HIDE_RIGHT_COLUMN, t2.USER_LANGUAGE, t2.USER_MOOD, t2.USER_RELATIVE_TIME, t2.USER_TIME_OFFSET,t2.USER_SHOW_ALL_GRAEMLINS, t2.USER_AVATAR, t2.USER_TITLE, t2.USER_CUSTOM_TITLE, t2.USER_NAME_COLOR, t2.USER_SHOW_LEFT_MYSTUFF
FROM ubbt_USERS as t1,
ubbt_USER_PROFILE as t2
WHERE t1.USER_ID = 341
AND t1.USER_ID = t2.USER_ID