SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fc81bed89980ef7d2eea0159508de762369d4a68ecdd99aff030258cdc601bf' 
  AND token = 'u9s54Jw48KowcuhXAfXriF02yjpXgPpuTYG0A6ZdsHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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