This is a painting of the Martyrdom of St Andrew.
This type of cross is a saltire cross, also called Crux Decussata, and now called St Andrews Cross.
For more information about Saint Andrew, read en.wikipedia.org/wiki/Saint_Andrew
This painting is exposed at the Casa Nacional de Moneda museum in Potosí (Bolivia). If you know its origin or have more information, please post a comment or email me.