You can configure patterns to hide files and folders from the explorer and searches.
Open VS User Settings (Main menu: File > Preferences > Settings). This will open the setting screen.
 
Search for files:exclude in the search at the top.
 
Configure the User Setting with new glob patterns as needed. In this case, add this pattern node_modules/ then click OK. The pattern syntax is powerful. You can find pattern matching details under the Search Across Files topic.
 
    {
       "files.exclude": {
        ".vscode":true,
        "node_modules/":true,
        "dist/":true,
        "e2e/":true,
        "*.json": true,
        "**/*.md": true,
        ".gitignore": true,
        "**/.gitkeep":true,
        ".editorconfig": true,
        "**/polyfills.ts": true,
        "**/main.ts": true,
        "**/tsconfig.app.json": true,
        "**/tsconfig.spec.json": true,
        "**/tslint.json": true,
        "**/karma.conf.js": true,
        "**/favicon.ico": true,
        "**/browserslist": true,
        "**/test.ts": true,
        "**/*.pyc": true,
        "**/__pycache__/": true
      }
    }