Create Layer From Selected Features DOES NOT create a DYNAMIC layer. The resulting layer is not dynamic at all. It is based on an FIDset.
If you change the source data, the FIDs will change and your selection layer will break.
There is no where clause in a selection layer. It is based on FIDset (the FIDs that were selected when you used 'Create layer from selected features').
Please note that if you add or remove records from the source data, the FIDs will change, and your selection layer will show incorrect records.
You are confusing the selection layer with a query layer, which stores a where clause and is dynamic.
EDIT: The list of features for a selection layer is stored in memory. It is bad practice to use selection layers other than for temporary work as there is no way to recover the original selection once the selection layer breaks.
To find the list of features in a selection layer, you can use many different methods including SearchCursor to build a list of IDs.
Something like this:
OIDlist = 
with arcpy.da.SearchCursor(layer, 'OBJECTID') as scur:
for row in scur:
From comment by crmackey:
There is also a built-in way with describe to get the FIDSet. This is a string, but is easy to convert to a list:
OIDlist = map(int, arcpy.Describe(layer).FIDSet.split(';'))