SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25ad02e7dfffb39a72e7cef42eaea794870ef88397118f83631b38a45515bf16' 
  AND token = 'Syn5qCAA37TSVYZts01JzHkXvGwIqsqkjQrV/cWp3NI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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