SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1fcdac73d0cddb4fcd2ad34588ce483c6fb246e732415ee938cd3e5d7fcf74d2' 
  AND token = 'fxVAMfH3idzFntbTwmVcjeYjiJKaY5covrZPbce+980=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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