SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '558bc5794d694c938047d7961ce99efc2bbeed868848551cd90e3b56402ee6ee' 
  AND token = 'aj0RQowDzRRnmt0l+CucG3Kq+kyBWxmNqotWZE+CF4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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