SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '041ead2ecc9d8ea85bd6d78d6e6d8db85d7756ea69aa773dab54d9663a5f39af' 
  AND token = 'Lv669IRrRzWuw9jGHcbcedO3Xfmlt669jT26kiikrEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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