SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a623099f880413eb140849bcc22099b43c427b15d7dbfab0ebac21e5195ffe2' 
  AND token = 'n9d0biZxAV9kLyjW0820iiRY3YlL0/kHHMG+5gzmm6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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