SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6156f1552c69f36023a6305e5b255ac78e0912f6ebacc47a49bb2547e227e49b' 
  AND token = 'oVBoHjBKxFG+49OqpIAdQzo4n9nrvmfgMs8/7QOeSj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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