SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7bef21ed633e2427cce874e564142de9e17a412958ec03cf700f84ddff3ea7db' 
  AND token = 'SDVfgnur35valVWm4i61RjVYlrfcDS1+tYis5fRfwdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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