SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cbeb6bb082867a4c7cfaa31c6569570ce129014d1d1816e60efb446addddd8e' 
  AND token = 'aVrzEnKQ6SnSFL/XygKIeuVr68eawxdXRVUS7SWPqlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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