SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '842aa5e73ec7dfe9e30cfe8c8e6dde766ef7354b748c7b2fd89c6d476da38048' 
  AND token = 'tUWm2E8HxVw7JyTulNq0HtRZwATRlGWVw/7nb5gY2cU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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