SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca364488240f552d4378b02e9953cbe94ca484329f8d03ca710a4daa2e87d0ee' 
  AND token = '3Hw/+0DZcVIGhNsqZ0bD1u8pCzKBq8zUpsHkOA3VjRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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