SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fff4a0201ad95f8b685552d2583f85f76f9ca5a37d76d9a840b664182b97e23' 
  AND token = 'Pzl7lraSgPUyx32itNhO0VgndHXCTQconuwwFjBSRMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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