Ah nice, so you could do something like this then...

SELECT top 10 
timestamp,
json_value(json_metadata, '$.contractPayload.symbol') as symbol,
json_value(json_metadata, '$.contractPayload.quantity') as quantity,
json_metadata
FROM Txcustoms
WHERE 
CONVERT(DATE,timestamp) BETWEEN '2021-01-01' AND '2021-02-28'
AND [tid] in ('ssc-mainnet-hive')
AND json_value(json_metadata, '$.contractPayload.symbol') = 'DEC'
AND json_value(json_metadata, '$.contractPayload.to')  = 'null'