SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2aff1589db4cc4a240b7564c005c80682ffa5fb06d4538a69a295bf56716d11d' 
  AND token = '2sdnA36FY0MzKH5DXVSG/5OyBjWjwzHTY5h3WFkJcro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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