SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05b7ad8a445bc9ee96e0b5748ce6aa3e2cb0a7221a3500aac073b645eca35499' 
  AND token = 'fnANfVJGpzcxqviziDj/eXsqg7Df0ZXjWskv3+uIViA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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