SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '919fa665a5e4fe3fc9a833237fe11750e82c75d8c98db62d1a00a17bf5337345' 
  AND token = 'HwB8/UlyWulUB0TVW4cROV2WXeqL8BYvqGHbKzwJYEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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