SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbfe8d2a239a4068f4dcbe86362ae5338aceae8049d7a8a4740237e34907fe05' 
  AND token = 'ht9qnf8ClylXwofSrdIfH/gYhmqzGtPjDbsAmneBrU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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