如何查询，然后在短时间内处理大量的数据

I have a large table of orders. At a set time, I need to send an SMS message (different content for each one unfortunately) to a large chunk of them (based on if they've opted for the message and if they included a phone number). It could be 200,000+ numbers in a fairly short time frame. (it's not really that high now, but theoretically could be and want to build as such).I have a large table of orders. At a set time,