SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0af6cd1de7d142bf1cba38abbd8544c3219c30727437759fb878a89514475f12' 
  AND token = 'Usat1gUkWIWmBBku/ASpDBjgrm8VrzPBvY6k3k0JCEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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