SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b31d2a26645ba8e18540b46b1d1b6181c06334ffd334edcdd91f0271d91e48e8' 
  AND token = 'JuQLJKlc9WjKpQd4wFQawQbs8OM7ydNFJVH3xXz3uig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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