SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10bb235f5fe3afc0a578fea477769b792b52571ce47964b6c85ea2513a30fbf9' 
  AND token = 'koDV2glfiBVBpVULshq11XG1VSqPusnPoYz2wYaY+L8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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