SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d67587e7a923cd166a4f6ae24f7422a59c10fe5a32b916355e728bee8294ef6' 
  AND token = 'BwZJP3G3UvrVbBRulsmOVD4DJVqqYtxTW3/4Wk8vWJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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