SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff23547cdf513c7a40a7b067b6089cd8e1961acdcc58fb0ff9b2097cb203ed3f' 
  AND token = '5qz3ICgGGqwsPz+kC074EJlHXta7u4eZ1GaDRY8qnTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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