SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9960706fe2e9a89f1e0b75474895e941645bc193662f0c71dafd9770cb07ce37' 
  AND token = 'TknRCyKpHrQit3Q8o4wibeE6Qw2ahCmQXo5FFkZbhWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00083

JSON explain

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