SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '417ba02f96cf8e3bdc6c4857a6323947fcce424785d4976ff59e68fa8f2122b3' 
  AND token = 'KXc9uN2qCH4yDMDlD/v1rBPkM3NEiqLk2xzGk+xYQFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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