SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbc97c21cc78e30b785703d742afcfc092cb894952d93bd2d34cdff43fad82fe' 
  AND token = 'yhgJ6gHBqh6eonsHg03/7QzyJmkGBaA4xKuhnu2ZDCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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