SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb3e383c852bb4b1838840dc8b506f8550341985c646bebfa08344de3881f4bc' 
  AND token = 'p2wyevHu+tNC1v1+J2uiux7RsWuG371+7yuWUKRJtZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}