SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '490875e7e7e39af8f1177e7e37ccc4f2f5ade418ae8ad72f0c4ba62d8747e3f0' 
  AND token = 'DuNac/i+/lTn6Ly+GDsCN6wfYv+CzgmDF3wkIPXYOCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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