SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c2bbc90f1f54607bca9a98b9db863d86b3e1526616e74b9cfdd849df1a714fa' 
  AND token = 'pQyPvJmUOLErQ4+Q3DVGzqPsPMf2lkFqk8eZoq7BqqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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