SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fefc0e221203668f1fd9e8ef54c256339d6cc51f5067261f4cee88561bab4df' 
  AND token = 'V2h3FTPi0tZwBCbJQOBRh2KsAZru/5oIkBjKGaRkPQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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