SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc0df66fc92360ac337ff60ddac7af30804ca9ddbd1f2f8697004efbe40d429a' 
  AND token = 'vVLZc6YaXoeOuSnE6Po6QRLvveQvCDl4BXVXpiZ3gYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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