If the lockis active as you are demonstrating, is because the VM is powered on in this ESX but are not being displayed on the inventory. The fact it is locked by the NIC MAC is not important - the UUIDis just an identifier and it uses one of the nics to be composed - it really means the ESX that contains this NIC is locking the file, not the NIC itself.
Try to do a "ps | grep -i VMX_FILENAME_WITHOUT_EXTENSION", for example: if your VM is named "VM-DEV", try "ps | grep VM-DEV". This should bring the parent PID of the VM process. If you see 4 or more lines on the command output, check the PID that repeats (parent) and do a "kill -9 PID". Check if this unlocks your VM. Be careful not to kill other VM process 