SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63d77fb95f800b53344b07be7ca1c49427f87041c388e55bf11f5239bbc30bc0' 
  AND token = '/13a3ZwYLBNB5ESUUnY9RwHa1VWqxq2dMAOyXJpVIw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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