SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b88cde1bdafdde08d03be5e69318fc581c8cbc85b39d4d384ba22c31409f7a2' 
  AND token = 'JTz6mBcHGOKt5TondfAgzAn6IGrRThrcUBF8UqHOG6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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