Hi
1) It appears that you have commenced your 3rd year of lease rentals and about 23 more months are left under lock in clause.
2) In general a Lock -In Clause should mandatorily be accompanied by penalty,breach or compensation clause so as to define the extent of compensation.
3) The legal position is that the lease agreement should explicitly quantify the extent of damages to be paid in damages to be paid in breach of lock in period of the contract.
4) It appears that there is no penalty or damages or compensation is mentioned and so the courts will generally presume 2 months notice period is a just compensation for both sides.
5) Remedies in case of breach of a lock-in clause is same to that of the remedies for any other contractual breach i.e., damages and specific performance of the contract.
6) In your case, since you are planning to vacate the premises during the subsistence of lock in period the outermost limit in which courts may ask you to compensate the owner is by awarding 2 months notice period + another 1 OR 2 months notice period which appears just and equitable to both the parties.
7) Hope this information is useful.