To get the user you can do
select userID
from your_table
where website in ('website.com', 'foo.com')
group by userID
having count(distinct website) = 2
but if you need the complete row then do
select * from your_table
where userID in
(
select userID
from your_table
where website in ('website.com', 'foo.com')
group by userID
having count(distinct website) = 2
)