SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7554333f03db1ae0d968bb52a140512fda4f91e81b04190228f0ff289d12aab1' 
  AND token = 'Aj70cdGtGrdOtWRr0wHcfuHr8K47ABPfdCaNOgpSnJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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