SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '233af5d98bb8fab380e75f39631b8ec9d26893264e4da505c603ada26b3b44bf' 
  AND token = 'qxRj39MeiBm0xBYRiAQ9Fa2+rsDHRZPUzEEzMucMLfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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