SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c40470e955bd1b067c76d9c2b4b1b5aac9c2c584ab70db3baeefb9af9afe69e5' 
  AND token = 'mSF7FIgVbQSvHbQpxiKZGzpc1/QjbZcbCfgwtNeW7pE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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