A favorable judgment is valid for five years during which you can enforce it. Once enforcement has begun, there is no time limit. If the debtor currently has no attachable assets but in the future regains solvency (finds a job, receives an inheritance, acquires assets), you will be able to reactivate the execution and attach those new assets. There is also the possibility that during the enforcement process, assets that were not initially known may appear through the asset tracing mechanisms.