SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84c5ffd04f56807cb8af79ef92984c7897d2cedcdd3bb19a14db1e31be137cac' 
  AND token = 'XokMxKCbnRWIVkKji2NB1X/sgYhnIGVZwU8yiqsfwJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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