Table subscribe

subscriber | subscribeto (columns)
1          | 5
1          | 6
1          | 7
1          | 8
1          | 9
1          | 10
2          | 5
2          | 6
2          | 7

There are two users that have id 1 and 2. They subscribe to various user and I inserted these data to table subscribe. Column subscriber indicates who is subscriber and column subscribeto indicates who they've subscribe to. From the above table can conclude that;
user id=1 subscribed to 6 users
user id=2 subscribed to 3 users

I want to find manual of subscription (like Facebook is manual friends)
user 1 subscribe to user 5,6,7,8,9,10
user 2 subscribe to user 5,6,7
So, Manual subscription of user 1 and 2 are: 5,6,7

And I'm trying to create SQL statement..
I give you user table for my SQL statement and I think we can use only subscribe table but I can't figure out.

Table user

userid  (columns)
1
2
3
...
...

SQL

"select * from user where (select count( 1 ) from subscribe where subscriber = '1' and subscribeto = user.userid) and (select count( 1 ) from subscribe where subscriber = '2' and subscribeto = user.userid);"

This SQL can work correctly, but it very slow for thousands of columns. Please provide better SQL for me, Thanks.