SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf34a28d712e46aa0e58d032cd225669ff303569df47428378b961ff23330a11' 
  AND token = 'yyseo5jtzXwC2JVfGA93rj0Jq8rFbpjvdfKhzGLYMTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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