dev.mysql.com/doc/refman/5.6/en/innodb-restriction...
By default, an index key for a single-column index can be up to 767 bytes. The same length limit applies to any index key prefix. See Section 13.1.13, “CREATE INDEX Syntax”. For example, you might hit this limit with a column prefix index of more than 255 characters on a TEXT or VARCHAR column, assuming a UTF-8 character set and the maximum of 3 bytes for each character. When the innodb_large_prefix configuration option is enabled, this length limit is raised to 3072 bytes, for InnoDB tables that use the DYNAMIC and COMPRESSED row formats.
1. можно уменьшить длину поля name до 255 символов
2. поменять engine для таблицы на myisam (например)
3. установить innodb_large_prefix = true в конфиге и у таблицы указать формат строк DYNAMIC или COMPRESSED (написано в доке см выше)