If the record that you are retrieving from the database table is not dependent on the data within the row from the spreadsheet then it will probably be the same for each row - is that what you are hoping for?
In this case, I would consider using an Execute SQL Task in the Control Flow to retrieve the record and save it to a variable. You can use a Script Component in the Data Flow to copy the values in the record from the variable to the appropriate fields in each row. This will mean that the lookup data is retrieved only once and not once per row which is slow as jn29098 said above.
If the target for your Data Flow is the same database as the one from which you are extracting the 'lookup' record then you could also consider using an Execute SQL Task (in the Control Flow) to add the lookup values once the spreadsheet data has arrived in the database (once the Data Flow has completed). This would be much more efficient.