SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e89cd42e49516d30acc70abb6b60357b40ea5b8942c87f7ae991236aa3cdca2' 
  AND token = '9hWjYOUB5sXAWK5pClfanLpSqY2IdNKRJEOnkRyRgBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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