SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a196769279dc33cbf7b749936d06a0f3f9480e66adf4a15230cfa91d84ab757' 
  AND token = 'CueiyiABHHf8YNSYD+4eyhu/qCDM2tH/MTtNRu9xcz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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