SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '287b06bd09380024d7339f2f5b1c03b66199b8f5d72c832280cfd3dd910f57cb' 
  AND token = 'Uw0ZTafYiS350Ia+r5ncoxeG1HTxOXmmUAM1tYAbhwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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