Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5476dc68cfba5800b30c3ab1ee9dbbfbe4bc84f5e479dc6d5089a8b596560355' 
  AND token = 'rmcMtNQbiDxEYz0szTHjFotpTWDdBjEeW6fMbfA/zXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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