Whether it’s allowed or not I don’t know, but it does seem like an odd thing for a Christian to want. We should want what God wants, and for most of us it can be hard to discern what exactly He wants. We do know that God wants us to go to Heaven, because that has been revealed, and since we can be more sure of this revealed fact than anything else, we should also want this above anything else.
Unless you’ve had a divine revelation you can’t know how your life is going to turn out, or what God plans for you. You can get a sense of this through discernment and prayer, but you can never know. He might want you to live a long, fulfilling life like you hope, or he might call on you soon. Either way you should trust that God knows best and eagerly await to see his plans unfold.