SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43dc22819e7b216e3877c4d797dae7c9d8c50da36343b6fa70904fb3ab5bc5e0' 
  AND token = 'RLFA5hT2d+XkeDVFYbAga0wuLGNOPxttzEggT6HClcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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