SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49fbf434da07e854acf2e94d880222f9fa0321026aab8e1fac87fcf95222aa88' 
  AND token = 'rjccQQjVpUMWQ4JzGjZhgtLfSgpBuEGRtJ5Vsn7rl40=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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