SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eed46c5ebd743e94b4aad179e8c21a555cdbf790a4c5b34bf11d96561f10642b' 
  AND token = 'xf+XaRAUDjwrAJY9xzNPjeIvoGLS+OwL68+nJfKGKpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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