SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f893430d316c2979bf15c5378f613a2dc3f1d124842c1c3bb58eae5488ddea5b' 
  AND token = 'sJ3sNKFBNwC5deLVYTY7D29eHEyIGxrHSrXLNI9Bunk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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