SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f1b11b31d5e0a9a02847ba96507fbc818c024193d04b28b86f5ff45f310cd3c' 
  AND token = 'JeN8Z7w9rX9Ct7w0WXZRjuee+OEzZiXYeYRjB7vwStc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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