SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29df6be647d443eaf616b6bcaef2e1f638d5b455a2c0f0d98974b59c904adb97' 
  AND token = 'kbXtkTts6Blw58JOWj41dU8kf/eXOLbUSbaTcMBp604=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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