SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '513ea4c0d368868d71394494c1cfd5a29726c8456358f2b3ebbf362cc846c629' 
  AND token = 'aAb88r/E72n/+9nCCkzptVpWurhIgjrxJbZnYD8vPd0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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