SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '272828aad638359e5c35f1aeda4c7945597f9e03e63cb4e54fb52743955cfc14' 
  AND token = 'OzxMY7FJzVPX9bLkXuzqR2FkBWWuiW+8ZbhtBvW5jCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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