SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b92c0daca5a828b49a634ad737c7aecde25f6d52c42f33be325b7ff36bd4bef' 
  AND token = 'V8kE/GcCrepHoIE9m42enmtWYGdmi+k3XhMQSfm3zEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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