SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fd4e02e593368ac1b36900677d9f7c9a69dcd4ab42dfafccf249313972e282c' 
  AND token = '5gX8lZELiYQJWuHYDw+7+FwlsUiGJY7Zw5CXzjuTjHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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