ASSA has their own lock lubricant (ASSA Lock Spray) that they recommend. Hard to say what's in it because the MSDS/SDS only lists the propellant and "proprietary" ingredients. However since they say not to use graphite or silicone, you're pretty much left with Teflon (PTFE).

More info from ASSA
http://www.assalock.com/en/site/assalock/solutions11/care/Cylinders
ASSA cylinders are a mechanical device and like any mechanical device they need regular preventive maintenance. At the time of installation cylinders must be lubricated with ASSA approved lubricant. Wipe off any excess lubricant on exposed surfaces. Cleaning and lubricating the lock mechanism that the ASSA cylinder is being installed into is important as well. ASSA cylinders should be lubricated at least twice a year as normal maintenance.
Do not use graphite or silicone lubricants. Use only ASSA approved lubricants.
Do not expose ASSA cylinders to chemical wash.
Do not paint any cylinder surfaces.
Do not over lubricate ASSA cylinders.
(If you suspect your cylinder has been over lubricated or suspect excessive dirt or other particles or debris, thoroughly flush with ASSA cleaner deicer or use an alcohol base electrical contact cleaner. Let dry or dry with compressed air then re-lubricate with ASSA approved lubricant.)
I figure you can always go with a Medeco approved lubricant - which approves the use of Teflon/PTFE:
Medeco approved lubricants
http://www.medeco.com/Other/Medeco/Downloads/Key_Lube/1/Cylinder_Lubrication.pdfMedeco Cylinder Lubrication Approved Products:
Medeco KeyLube 2.0 Multi-purpose Lubricant PX-KYLUB2-03 (5.25 oz.) Aerosol can with spray tube
Sandstrom Poxylube CP-200 Air Drying Solid Film Lubricant Poxylube CP-200 (4.5 oz.) Aerosol can with spray tube
Synco Super Lube Dri-Film Lubricant
Super Lube Dri-Film (11 oz.) Aerosol can with spray tube
Super Lube:
http://www.super-lube.com/drifilm-aerosol-ezp-69.htmlSuper Lube® DRI-FILM lubricant contains sub-micron sized particles of PTFE powder in a solvent base. When applied, the solvent carrier cleans and carries the dry lubricant powder to the components to be lubricated, then evaporates very rapidly, leaving behind a protective shield lubricant that will not attract dust. The dry coating provides a low coefficient of friction which gives excellent lubrication and release properties. Super Lube® DRI-FILM can be used on wood, paper, glass, rubber, fabric, leather, vinyl, metal and most plastics not under stress. It has excellent thermal and chemical stability, forming a natural insulating barrier when used on electronics.