SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3829fc37a59602c97fb94f5a578b51ca27d45375db41827355f5bf0adc3b2815' 
  AND token = 'RMwK1IvBJaA7dmT+6s5cInmC0t9oAWyrlhQiw59FxcA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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