SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a981f266e9e678dbcc3c71c62f69d1ec51f98dff2c4b213802d7d6fa1f5f6fe' 
  AND token = 'wuOzpC5h/7XTaQA/CnscZeYV6BPM58VFJW+pzeOHCjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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