SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2162a57ca6dea2bcc568bf801aeed6374803ea9725baf1a9038abff93c40e665' 
  AND token = 'mBKmVDMJ2tnBxLwgzORZaNsyabCbW8SHktUzum1aXIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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