That would require a very creative reading of the constitution. Congress could pass a law overriding it, and SCOTUS could could uphold that law under the commerce clause (land value in California affects land value in Oregon etc...).
"The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people."
California is one of those states, so unless you can show where the coastal access law is prohibited elsewhere in the constitution (and that prohibition has been incorporated), California has done nothing unconstitutional.
nor shall private property be taken for public use, without just compensation.
Done.