SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0206d8437c4a302725b1501c5fa1b1f912f224a632adfb05f09a2e08d20f9cb5' 
  AND token = 'LLIAeClbCcH8q4QYAVWLoKhE8izvmqGSXdVL/wSidbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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