Change primary key for flag_counts table

I build a block of popular users on my site using modules Views and Flag and discover it is a the longest SQL request in my life. It takes about 3 min.

There is SQL:

SELECT users.uid AS uid, users.picture AS users_picture, users.name AS users_name, flag_counts_users.count AS flag_counts_users_count, users.created AS users_created
FROM users users
LEFT JOIN flag_counts flag_counts_users ON users.uid = flag_counts_users.content_id
AND flag_counts_users.fid =2
WHERE (
users.status <>0
)
AND (
users.access !=0
)
ORDER BY flag_counts_users_count DESC , users_created ASC

I tried modify indexes for table flag_counts:

ALTER TABLE `flag_counts` DROP PRIMARY KEY;
ALTER TABLE `flag_counts` ADD PRIMARY KEY ( `fid` , `content_id` ) ;

After this the same SQL became much faster - 0.28 sec!

So I think the field 'content_type' is superfluous in primary key of table 'flag_counts', is not?

I didn't test version 2 but as far as I can see the function flag_schema using exactly the same definition of primary key for table 'flag_types' (line 300):

    'primary key' => array('fid', 'content_type', 'content_id'),

So I guess It should be changed to

    'primary key' => array('fid', 'content_id'),