>How to make this data for ever in cache? :)

sp_tableoption "PinTable" will cause a table's pages to remain in the cache once they've been loaded. Understand that by doing this, you are overriding SQL Server and may affect it's performace. In general I wouldn't recommend this except for a, small, frequently used table.

You might want to check the query plan to see how SQL Server is solving the query. An index might be missing.

-Mike