SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88e88399bd3a479a7106d47ec6d752503745010d3ca5adb424b0b8e0743fa6cd' 
  AND token = 'wNZCBSGC1irKZMw+OlJQGWE7Gh2kxT8VbjZyvPmeRA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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