SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66785c8b7690f0be065c86676802d079db9896de5167b26e989a6511454ce461' 
  AND token = 'APOACQAudXN20RYo1QjW8PR6dXR5f5aG6NAeabzPstM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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