SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23d9bec8172b97554a04a1a325ff00c7f3f9b61c8c24eb64526f11a94d1a2f0e' 
  AND token = 'JNOmj6KgvAWQIiYHYC72OJ/iVCPN22u7UbsgSEJsKtk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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