In MySQL 5.7.3 index condition pushdown is also working on partitioned tables as stated here https://dev.mysql.com/doc/refman/5.7/en/partitioning-limitations.html.
Previously, index condition pushdown was not supported for partitioned tables. This limitation was removed in MySQL 5.7.3.
Can't find any information about MariaDB 10.2. I know it is in RC stage but maybe somebody knows about it.
In 10.1 without partitioning: Extra: Using index condition; Using where; Using filesort
In 10.1 with partitioning on: Extra: Using where; Using filesort
Thx