1.) The actual bracket/anchor (I do not know if it comes with the bolt and washer but #2 is the part# shown in the Lexus/Toyota diagram
73719-50010 Bracket, Child Restraint Seat Tether Anchor
2.) The bolt/washer needed for above (not sure if it is included)
90105-08253 BOLT, WASHER BASED H
I also found these parts to be cheapest to order locally from Canadian dealers (you get the wholesale US price + exchange and no shipping cost) vs the US because of high shipping fees on most sites in the US.