SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ff8199c70091604625332fa0db1f9c1ff7b1859f6440ae13f6445724a2942b3' 
  AND token = 'kUdZ+yz4ICnuiryJU7A37NNbBiJsCeSRm6pyzGcmAl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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