SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35e1bb8defe686648b789b1cafd69d5e0e265151bbf2dc0675ac8b778bd55c54' 
  AND token = 'vACVco8Fs+cUhoAmPwcdNHdul37FnLdMVKTcJaunXEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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