How to speed up an X++ SQL Query

I am trying to Select the latest SalesLine with a specific serial number.  Here is my query:

Select FirstOnly SalesLine Order By SalesLine.createdDateTime Desc
        Exists Join InventDim Where InventDim.inventDimId == SalesLine.InventDimId
            && InventDim.inventSerialId == "Serial Number";

It is very slow, and I need  a way to increase speed.  Should I add indexes on InventDim.InventSerialId and SalesLine.InventDim?

Thanks.