{"keys":["25094"]}

JSON_TABLE(textvalue, '$'
COLUMNS
  (stringvalue VARCHAR2(100) PATH '$.keys')) AS jt

{"keys":["25094","36316","36317","40836","45223"]}

with sample as (
                select  'mystring' col1,
                        '{"keys":["25094","36316","36317","40836","45223"]}' col2
                  from  dual
               )
select  col1,
        key
  from  sample,
        json_table(
                   col2,
                   '$.keys[*]'
                   columns
                     key number path '$'
                  )
/

COL1            KEY
-------- ----------
mystring      25094
mystring      36316
mystring      36317
mystring      40836
mystring      45223

SQL>