SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ef3f0f6a634c544af51d6ae4384145339046b8eda89234c76977c9851673b64' 
  AND token = 'L0beUxQsX/byTi6RMJV7cgLgKTEQwGgKrzF5dOx12AU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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