SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cf5e24eaaf7e31363d125f87aad95c5659e4cbd971be6f4dc0c70fdbd520c37' 
  AND token = 'V/NWo80VobYnMWfWDy9UlOBsGsoZ+dmMgSr9jMXUhEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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