That's not valid MySQL syntax.
This is valid MySQL syntax:
INSERT INTO feedback.app_v2 SET mycolumn = ?
Yes, it is safe from SQL injection, because the dynamic value is restricted to a query parameter. This is not combined with the query until after the query has been parsed, so there is no way the parameter can introduce unintended syntax.
If the NPM package can do string substitution to put the key = 'value'
syntax into the query string, that's not a true query parameter. The assignment must be part of the query before it is parsed, but proper query parameters are not combined with the query until after it is parsed.
So you're depending on the code in the NPM package to do the string substitution without any bugs that result in SQL injection vulnerability.