SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b1de1f0a96fa2431fb5b8dd7355e2381a9040f7a98be16c197afc955e563563' 
  AND token = 'juyCkVt/XJjnsitutlX15bkH94Kh+LlSvvuqjoegHkQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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