SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9181e7e12e954c84b72b86541f53fe0f07b3fe2268d5d7b59f0a3f681227e31a' 
  AND token = 'rsvI96qFnnBebG7YU1BZMLG+E/TBQC5OZ9hNYdKcRcA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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