SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ea2e6c495d5ab358075f965c83f0062b95a4851ac15ce8a47ffa25184b47ff1a' 
  AND token = 'J31kRbUEB+NzackDNz3H7m32RTLyQcesQ0MvwrBBeZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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