如何将4个字节的表情符号保存到mysql中？

mysql version 5.5.41 (MariaDB)

ALTER TABLE msg_ms CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_bin;

I have convert my table into utf8mb4 but my col (msg_desc) data still showing ???? when I try to save 4 bytes emoji. How to solve this problem?

CREATE TABLE `msg_ms` (
  `msg_desc` varchar(191) COLLATE utf8mb4_bin DEFAULT NULL
   PRIMARY KEY (`msg_code`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin