SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc3882a3c7284fb62773850c03d866431491734dadfaf375f978d2f8d53798ae' 
  AND token = '5Qr9Qqnc4rtj9PCExyBKPXPN++OpoGVtEu/gykL02OA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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