SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '28454fdd4b892cf73e21cfb17db61e0da7bc13d4630ae8df192c56f944e92cce' 
  AND token = 'fSVkldnT0Zxfjcd8a21SIONvnSqOeHbXD39NyT/9hlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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