SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87bb7d2fedc3c6b60d45ad93087eab49664b87c1e4bc91268ee6c5bf6bdfee04' 
  AND token = 'Ve0VUs2PcWcTQYKnBxe7VWi9lSzlDs0ivqKnHsgRfGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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