SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdbe7262ccba3311210c346848b5a5128658639f06ae4d512db9e8659dd7ecbb' 
  AND token = 'mnoAP6uyRKsn/CZiqdGIQQUuBLNqJK4pFGvl3y4KZ1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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