SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '504ab41dd25e95d43ccda9c1696babd549460cdb8d3719a2554dd0b4581c9013' 
  AND token = 'BgbgC81XNVCIck00SVIQGRxPP3zGh/h3hLqCSp6nBkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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