@Configuration
@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    public final static String ROLE_ADMIN = "ADMIN";
    public final static String ROLE_USER = "USER";

    /**
     * Determines the resource access for different account types
     */
    @Override
    protected void configure(HttpSecurity http) throws Exception {

        http
                .authorizeRequests()
                    .antMatchers("/user/create").permitAll()
                    .antMatchers("/admin/**").hasRole(ROLE_ADMIN)
                    .anyRequest().authenticated()
                .and()
                    .csrf().disable()
                    .httpBasic();
    }

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(inMemoryUserDetailsManager());
    }

    /**
     * Initially fills Spring Security with default accounts
     */
    @Bean
    public InMemoryUserDetailsManager inMemoryUserDetailsManager() {

        final Properties users = new Properties();
        users.put("user","pass,ROLE_USER,enabled"); //login = user, password = pass
        users.put("admin","pass,ROLE_ADMIN,enabled"); //login = admin, password = pass
        return new InMemoryUserDetailsManager(users);
    }
}

@RestController
public class MovieController {

    @Autowired @Qualifier("MovieService")//not relevant
    private MovieService ms;

    @Autowired @Qualifier("CastService")//not relevant
    private CastService cs;

    @RequestMapping(value = "admin/movies", method = GET)
    public List<Movie> selectAllMovies(){

        return ms.selectAll();
    }

//the rest of the code..
}

@RunWith(SpringRunner.class)
@SpringBootTest
@Transactional
public class MovieControllerTest {

    @Mock
    private MovieService movieService;

    @Mock
    private CastService castService;

    @Mock
    private ActorService actorService;

    @Mock
    private UserService userService;

    @InjectMocks
    private MovieController movieController;

    private MockMvc mvc;

    @Before
    public void setUp(){

        MockitoAnnotations.initMocks(this);

        mvc = MockMvcBuilders.standaloneSetup(movieController).build();
    }

    @Test
    @WithMockUser(roles = "ADMIN", username = "admin", password = "pass")
    @WithUserDetails("admin")
    public void testGetAllMovies() throws Exception {

        List<Movie> movieList = Arrays.asList(
                new Movie("title1", "desc1", MovieType.newest, 10f, true),
                new Movie("title2", "desc2", MovieType.newest, 10f, true),
                new Movie("title3", "desc3", MovieType.newest, 10f, true));

        when(movieService.selectAll()).thenReturn(movieList);

        String uri = "admin/movies";

        MvcResult result = mvc.perform(MockMvcRequestBuilders.get(uri)
                .accept(MediaType.APPLICATION_JSON)).andReturn();

        String content = result.getResponse().getContentAsString();
        int status = result.getResponse().getStatus();

        verify(movieService, times(1)).selectAll();

        Assert.assertEquals("failure - expected HTTP status 200", 200, status);
        Assert.assertTrue("failure - expected HTTP response body to have a value", content.trim().length() > 0);
    }

//the rest of the code..
}

Wanted but not invoked:
movieService.selectAll();
-> at com.myproject.Controller.MovieControllerTest.testGetAllMovies(MovieControllerTest.java:87)
Actually, there were zero interactions with this mock.