Question regarding mysql index

Hello,

I have a table with the following structure:

id (int, auto increment), text1, lang

I also have created an index on text1,lang.

When I run the following query:

select * from mytable where name like 'cre%' I get 2500 records back.

and when I run

select * from mytable where name like 'cre%' and lang='en' I get 25 records back.

However if I run:
explain select * from mytable where name like 'cre%' and lang='en' I see that 2500 records are scanned.

Is that correct, since I have created the index on those two columns? My assumption was that only 25 records should be scanned.

Thanks a lot!