SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fbe6d4f5b8d5c3e820fc91d80581f67d33fed8ca39e5b6e1a73ed517792635f' 
  AND token = 'nGOUpp0PPEPg2HG4xoCxwQ9P+nUS9LFHtDuJZpvn9aU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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