SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9075df946ba03efc2f36065849ec7ee60353175764a7a1989ef40af69f4328b6' 
  AND token = 'rnppKBxZSYtfBzOfblhX5SdkhrKznNCMQZ9vEIxlK/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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