SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8846cc807b9fefdc0d0a7589b0cad3bfe10c49c5161ee0f7a3a4099a0ce8181' 
  AND token = 'YtO/6Oju+6mLyoHnNMrQ9OF1Izu2mGmMjWNZE/QB6fg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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