SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd7d8cc87bc6d82240e53e8c552fcd8e68f4b8371abe02f10dce893edd24ecbe' 
  AND token = 'jpfCZRfRVgFCj86URJ2Tzy8RpWPYWaJk/kusvzMiI4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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