SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a66cba002b94b751602df23e956a0fde47471a32f417a281b9acf67f4622134c' 
  AND token = 'RJ9ZShvC520MsxuT+B8OtYBHPnwpMJBecicI2GBWt+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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