SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '43d834d08380638bdd8c92c43fc48ef0335eac99ada742a8dfd1ae6e109d4bd8' 
  AND token = '2FO+7B850L4JtpUmx/xUnwcqao/2ogt6vGRHGB1tAtg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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