SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab075d72337755f5f012afd48f26f306811f04ce00243094ab800aafe9f4a164' 
  AND token = '7ioZXU0BeFpmahX0nIgIsamvJhZ9FYG1cO8yK3rvQHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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