SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '909ed8dff93ec157c6f0dd508ec26ea3c671b541b96d3200c2bf931b8c5b5559' 
  AND token = 'HuqCOKbj7ziKLBMd5Qsc+jORChYWGGoiQBj2iJ9A4pQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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