rewrite in to exists?

I'm on 7.3.4 and this query gets horrible performance. Is there a way to rewrite it with an exists or some way to get better performance?

select code, id, name, date_of_service
from tbl
where date_of_service in
(select date_of_service
from tbl
where xxx >= '29800'
and xxx <= '29909'
and code = 'XX')
and client_code = 'XX'
order by id, date_of_service;

Thanks!