SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a54f4da0fba118d89080375decbbc2d050b7bcafd84ea1c6eb8e8ea026ae1f26' 
  AND token = 'mqE+24j1a7AlIXjaSYUa3cTH8hWOLiclgZ8p1IMjwik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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