Those lodged in jail were identified as Shaji K A, Tharun Babu, Nithin Babu and Godwin O A.
They were sentenced to four years imprisonment months back on charges of not having the required job visa or work permit.
Chandy made the request in a letter to External Affairs Minister Sushama Swaraj.
The CM said the Non-Resident Kerala Affairs Department had sent a lawyer to Togo to provide legal help to the four persons.