SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '350596f5c65e658a400ba4f645ef68b989fd5bea642ba7d381571066cff6f3ef' 
  AND token = 'daWhMQrfoC9GFJmnP9QpDxxalMDjIYvm4NHdCFuAdFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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