SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '654a0b21c4845597cf2fd03138d64fea12cf3aa74744e3d1048af649528a5360' 
  AND token = 'FGUqM9KC3/doU1TZHnY/DJ79YDwgEi5xQ+WyPW6feOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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