SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77c792f0dee6f4f2e17ffa0a149b629465b12845f3e2afba0a3a8c332765b2f7' 
  AND token = 'SaWw0hE3GZQFyNDwuolLGdQjkvTpTKzhMxaGSxc5HbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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