SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf852e2f7bf2362eeaa6295d0685cbaf7812c568e1afc16dd43ea884b5300ca8' 
  AND token = '/BolhvWmzF+vgZ/8aAXO9aCmqOll4T1bjVs2hee+w/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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