SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4beedf14563c6bf00495ab2df6f83fc37b84ccbd45b708660ab1b17b2a564116' 
  AND token = 'uVuXkrJsyGoBiRDXtFk3rpI+eprj8up8ZZp3UDqLIsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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