Use 5V SD-Adapter on 3.3V System
The SD card is a 3.3 V device. The 5 V module with SD card adapter steps down the voltage for powering the card and has logic level conversion for card's SPI pins.

If you want to connect SD card to a 3.3 V board it is better to use a simple breakout board without power and signal conversion.

I do not recommend you to connect a 5 V SPI device to MKR SPI pins without logic level conversion.

EDIT: smajli analyzed in his answer the logic level conversion chip used on the adapter you use. it doesn't output more than 3.3 V and you can use it powered from 5 V. but it is still a workaround.