SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '047bfd0c18443da061f79692c8d8b9e8b5b779bed63a3789dffe1bdc31f7b308' 
  AND token = 'yMCIamUzQ4wwSOSQpgPhXEZpjapiBUXNOjFox6d/tvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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