enum query results strange.

[Tanner Postert]

so i am doing a query on an enum field:
when i do this query:

select *, id as vid, user_id as uid from video where (file_complete =
'true') order by undt desc limit 0,10;

the results are 0.16 or 0.17 seconds.

instead of saying file_complete = 'true. if i say file_complete != to the
other 5 possible enum values. the query returns in 0.00 sec.

there is an index on that field... shouldn't  the = 'true' query be faster?
i just dont understand.