SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d219d42f5fc13cddb249876caa359a6e6e43e18fa09d05e45397bb32e066540' 
  AND token = 'yA4aJlUtTT04Lf35hAGxDouR+fckYDSUbqk+MUplLP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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