SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f41640c1101d727a05afef7e3ce4ff982afde419d8b260fa1affe990c117bcb' 
  AND token = '8E/xbhiVp1F5z4ac+jJSbZu5CrgsBmaFtOSyYT8lbmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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