SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f570aec05260ec22a8d1f644ec9601b77b56c4a25506c011b771b3d2893de2b9' 
  AND token = 'uiaXylIKxfOVycvTVKG9wJv4dcCkgwikNZBm9YXW/n4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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