SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a52a63bf9066b9474b4f846bf3230e985adb9b97d749f6392fd2d3d6c8ebdec5' 
  AND token = 'TKSZPeCUCjIjuX6J+YYytnQBXzgMLhRWP3h2/9rW9rs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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