SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fc609fec30db0c5caf9fd4a54b36fd5f1c741ca816e432e341e69a651b5792d' 
  AND token = 'YQzfxpYjV7wwHH6UV5dphXAH93cOjaBlS48TgxqzBuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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