How to set a where condition on multiplication of two columns in Sequelize?

I’m using Sequlize 5 with PostgreSQL. How do I generate the following query in sequelize?

SELECT * FROM myTable
WHERE col1*col2 = 50
AND col3 = 'somthing'

Answer

Thanks to Chris G, I finally worked it out by using Op.and, Sequelize.where and Sequelize.literal. This is the solution I achieved:

MyTable.findAll({
   where: {
     [Op.and]: [
       Sequelize.where(Sequelize.literal('col1*col2'), 50),
       { col3: 'somethimg' },
     ],
   },
});