SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbe9f60acceaccd7c231c16cac96d1f60799f363db475e65cd2d65e87e83c423' 
  AND token = 'qggiD0Ls/yAJXEBKe0vttdLMUIxIfImqfTO2DMwhgS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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