SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95b680e6fc426857e636068f427a25322afaf23d92bc827a5a094a371f2a7d90' 
  AND token = '3+o6eU4mOuYsYUAGFtWbw1YtWCOT4S6tk2dXYhqxw7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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