SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6dd6729621192933ac497c331dd4eba631a1a149dac801fda13998791d52d66d' 
  AND token = 'xB7JHBragbGKyuFM73f4uSimWyyd4CGoAhe3jL4fcNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}