SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3f5574411bb62858fe87efbd2fc2dc057ea4cf90901fd79723e1727da6f40a5' 
  AND token = 'xlxbouqM5+/a/6hFukbLd4llZiV6cOvGTGosRPgkHIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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