SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd511fc28b4e21d049092bb619d430966dda9b6a064d85356faee908144d17719' 
  AND token = 'QAz044PS+MQwaXEx4cXo8czUwkUf1WhpldU5V9CfkdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}