SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d7561ffed288e8c5649bec782dd205bcd15a3595047065fce43a15a57b6c5f1' 
  AND token = '4Zp6x//TdqaEVZkaMppoTX2zYKbLdsHlIs1C2s1jGcA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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