SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c689c204329592ed42e367cb324d111d8588dd8133424ddc9aaf58bc7d181f39' 
  AND token = 'roWMrHBQvJ19jlMokWqmh7ViS/K2jh2m8pO0SfNKGDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}