SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f6dbaaf3c8c1a35cca37f9d1f7e0ecf5fe1abd551558154e417cc7224ab3922' 
  AND token = 'cPtSIYnNhVoem/MtsZdqgJZsIPvAULS5KE+CT+QeLno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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