SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed7eb96b70a380ff06309aa289d0439d10eaa61c355ef8642db95f4423851533' 
  AND token = 'tWg8tJ6aKlJNv2dVNcwh/8rw21uvMIFQFdT/dCrep0Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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