SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cbd2971613d2960e31a3cffa6ec57dbfd8fe95665b17aa5abecc8878f5fb0d4' 
  AND token = 'JGnNohYxy8jx5ypGZVh/Y7qqgmpPjlpbOTmAbCyZhsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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