SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ae890e4720391ae93dbcbd6ea2fbbbee362ef81feebf80d8e30172b5e192399' 
  AND token = 'C5phtzBPNieP2x4riZq7PUBpPkpNfzL5tk0woB5fz+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}