Here you can see, how we can get the column name bound with specific unique constraint name…For example:
select k.COLUMN_NAME
from information_schema.KEY_COLUMN_USAGE k
join information_schema.TABLE_CONSTRAINTS tc on k.TABLE_SCHEMA = tc.TABLE_SCHEMA
and k.TABLE_SCHEMA = tc.TABLE_SCHEMA
and k.CONSTRAINT_NAME = tc.CONSTRAINT_NAME
where k.table_name = 'table_name'
and constraint_type = 'UNIQUE';