SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0377f7618545e2a5a0e9479550ec60ef66eefc150e1cb966a68a10669256ed1f' 
  AND token = 'rDSTmy1BcmzE89CwFZXGQg6WaX4I3QMtwk0JekXcSvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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