SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f67b0cf5644d642dbf5377063d6fd62ca449209241e28b8e25437345d553df9' 
  AND token = 'HbPDCQG6qsqKZC55GVLH8NybO3uzqeaNCgLgjSXZWZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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