it seems pretty straightforward. try following command after replacing the authentication token (red part) with fresh one.
Code:
rtmpdump -r "rtmpe://s20e7fj8eqzqv1.cloudfront.net/cfx/st" -a "cfx/st" -y "mp4:11.02.2014/CS/CS_11022014_PI.mp4?Expires=1396345812&Signature=OojK3TNBhQwerm3J-COvw~P-Jf3vJ5G5LhvgSyByiplIPYUvjGwn2pDoDxd2FDJjAWhhZNqzjL7lKLAOBK0qyndDr-KJYpCugCasmfs6hMT70aFBCU92lX0OjueiJDcDq6Zpq3CtKbXntKZBY3YhMLr-tSy67bZyC3Ewvo0a4MQ_&Key-Pair-Id=APKAI7LSJFZ27IW5FDOQ" -o Test.flv