A parsing error that occurred on sqlite3 for NOT INDEXED expression.

## Fully reproducible code snippet
When I'm trying to parse the query below, a ParseError occurs:
```python
import sqlglot

query = "SELECT * FROM t1 NOT INDEXED;"
sqlglot.parse_one(query, read="sqlite")
```
error messages:
```
sqlglot.errors.ParseError: Invalid expression / Unexpected token. Line 1, Col: 20.
  SELECT * FROM t1 NOT INDEXED;
```