SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae694969ee1b3d560b014621072b44bb8682bbdbfd62e56c6a90dba8f0b4f883' 
  AND token = 'SAqJfM20dHiBDixqIH6+/pXDKj9X+9TkUkFrZAo0U1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}