Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d1a44d498c500b1acbd30e3fed42d9eff565b4e5f6610edc66d360d23e352a4' 
  AND token = 'PrKiqwWLFLAvZQYnd+5VqrJvpMKtMrdg/nMMbuzXUUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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