How to get value json in database

Halo Everyone,
i have issue in my query. My DB save data Json but I don’t get value or string. everyone have same issue?

capture and sample data below:

{
“flash_deal_end”: “2021-09-27 14:45”,
“engine_capacity”: “-”,
“flash_deal_price”: 8000000,
“flash_deal_start”: “2021-09-22 14:45”,
“flash_deal_activated”: 1,
“flash_deal_rejected_reason”: null
}

how I get value and print from “flash_deal_start” ?

regards,