SP ~ let us say with him giving Ansh's things to the police he is temporarily taken off the list of culprits(he may be back in a day or two).
Pankaj and Dubey are the only other people who were at the warehouse with SP, Shobha( not on my list, but could be wrong), the cops and Prashant's dead body(he may not be dead, could have teamed up with his dad). So these are the only two who could have taken the key from the dead body.
On scale 1 thru 10, 10 being the highest possibility of a culprit:
Pankaj ~ @10😡😡
Dubey ~ @10🤢🤢
Please share your views.