SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '89d66c322b8aeb17f8eaa4425d4f2ac1aba17d121238dc1a8cedd5e2757b5869' 
  AND token = 'GUX4LbGRla5ALhLfhr8RDwj7IFQR89pZlrtvcDX7BP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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