SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd7360f2924eca82541cce166e2191904f9e6876078acc38f9a5f3f56e5ee0f3' 
  AND token = 'yj6yniXCeX9KEft7VVuyncNYE7ia7binGg9fXoW7nCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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