SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '109b655df2e123dcdc42da3dcd327b829633fa82c0a088424939f624cf55b9f2' 
  AND token = 's9r6qLv3zjFJdErBFtQPCeYvCzBKQRll8eDreEfbrNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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