SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e1d12dfdb2a2ccb194f8b878e9ed67b65ea14a02b89ce646dee986d012ee160' 
  AND token = '3AWSVXtalAUM+KGoBqek9ZZzgvAzMfGiB/3wKVz7OCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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