SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8caaf58bfc61898185114cf9321a4ef04b997799346abda946ff93676b315a47' 
  AND token = 'l1g0yqjwbDHhGvbZoljOi5hKLnfsyGEQpsV7HMBVJy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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