SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c0d17d9235a78b80fae31f17a503048546b86c35d329dc534038ed864d83b7b' 
  AND token = 'E8f1Buvtdhc9vXmGNCQySFz2V/e+aB7l3ZPXSsaZjcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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