SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b613ac4bafb80baad69d917b9bc9d92866f8de248476b8e149a2f0662217ea9d' 
  AND token = 'I5Gr1YXgOX7H6XVvCE9Xv48yRXJcX+6SVp7SJdV+tek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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