SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '349ac2eccdeddb6b01b0142fba44a21beb2103fd30b18cabfebc3d7036bbd05c' 
  AND token = 'z+UJmVSsKGgE/KkodiCiuB5CZswWJKTsvmnljOPiFVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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