SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'deb4a5e94c466cde50e5ed3fb73ca6330732370b9253814b945158c47f796dc6' 
  AND token = 'KcifEuJvKpHQraZUNH9T2JXp5XihZKlCXZ+BSwPKoYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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