The interactive Bone Toy from Crufts (Kennel Club) is an excellent logic toy to prevent boredom.
It is up to your rabbit to work out how to get the treats by pushing or pawing at the lids to reveal the treat underneath.
NB: This game is manufactured for dogs but rabbits are capable of cracking these puzzles when there's treats to find!
Safety note: It is the responsibility of the pet owner to assess the suitability of any treat, toy, or other product. Please read instructions, and directions of use carefully. Always supervise your rabbit whilst playing or eating. Remove the toy if it is damaged, or worn, or if parts become separated, to avoid injury.