SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '794161e9b06c7bef8eb7cc408ac399b5d93e24acdbbde931ee0c65a7c2bf902e' 
  AND token = 'Z2GGBFuWvGVYgNkkaHDJB3XWYrvX+7rHdou0+K8pGEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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