How to remove unique key from mysql table
Use below query :
ALTER TABLE `table_name` DROP INDEX key_name;
If you don't know the key_name then first try below query, you can get key_name.
SHOW CREATE TABLE table_name
OR
SHOW INDEX FROM table_name;
If you want to remove/drop primary key from mysql table, Use below query for that
ALTER TABLE `products` DROP INDEX `PRIMARY`;