You'd have to optimize the source and I'm not sure what optimizations are available for Access - a quick Google search reveals this and something about indexes here but I'm honestly clueless about how Access indexes work.
It occurs to me that you could create a linked server to the Access database and then just schedule a job to run a query against the link.
@server = N'MyAccessSource',
or even query the source using
SELECT CustomerID, CompanyName
select * from
'select * from Table');
I guess this would save you the overhead of firing up SSIS packages and worrying about data flow tasks.