I suspect that the indexes on the tables added by your "book" addon are at fault.
Perhaps try running the following SQL statements via phpMyAdmin:
alter table book_authors add index ba_name (book_authors_id,language_ida,book_authors_name,book_authors_nickname);
alter table book_authors_info add index bai_id (book_authors_id,language_id);
alter table books_to_authors add index bta_map (book_authors_id,language_idta,products_id);
Suggestion courtesy of senior tech staff at GoDaddy who offered this feedback when I asked them if there was any reason why their server would be so slow.