SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f67acb2cb50d3e1e3faa1673f14188e230fc619fc4d26ce9d0d00dd2148eea4' 
  AND token = 'aGzqDv6qepZ+zhrw3qJrDCSKNOVYmAwfjdVemmFzHUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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