SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'eac5e03b788b279bd867b81b6c7b2b67c8662168091b9bf498531105edbdecbf' 
  AND token = '5ANobnYiGPx5Axc1Y6QmETS8RAY3Wlq4Lv+Q3U5z9+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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