SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b157dbf68351dfd3da3e512876f02a74a73e91c5dcb1352d1c727e58d5d066c' 
  AND token = 'wrMLYOXqKLv0VK1dq5tSbYX83Wgew9hAFbzmXrCzEfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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