SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0176722ca3f869f0acd4fdaa7e7381312db1787cb2e850aab4fdbd7c46b211e7' 
  AND token = 'ZYB5qki29fv8sdyKJFnhKeSToLZcC3/iHmjJNiRGpwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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