To success spend of OP_CLTV, following requirements must meet:
- nLocktime is required
- if nLockTime typed datetime detected, then value must satisfy < chain's MTP.
- if nLockTime typed block height detected, then value must satisfy < chain's block height + 1.
- if OP_CLTV detected, then its time parameter must satisfy >= nLockTime.
- At least one input's nSequence must set lower than max value #FFFFFFFF to enable nLockTime.