I imagine T-34s were used for quite a while.

Current active service per wiki

In 2010, there were eleven countries that maintained T-34s in the inventories of their national armed forces: Cuba, Bosnia-Herzegovina, Yemen, the Republic of the Congo, Guinea, Guinea-Bissau, Mali, Namibia, North Korea, Laos, and Vietnam. Of these operators, Vietnam possessed the largest known surviving fleet of T-34 series tanks, with 45. Bosnia-Herzegovina possessed 5, Yemen 30, Guinea 30, Guinea-Bissau 10, Mali 21, and Laos 10. It was unclear how many Cuban and North Korean T-34s remained in service.All the Congolese and Namibian tanks were believed to be in reserve storage or inoperable