SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e7c6eacf9206e858492a5273dd457d321a8ac4cdc4e1da379651c3719822edb' 
  AND token = '9gYumkpQETamocIx4+4xmtqtyJRNS07NgTkjVidUdIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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