SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2505ace9d05d34aa9a38ca1af7403f45dcc6220e435ade1ab1de87c9d8fd91a' 
  AND token = 'dMQXLl/lwsWbv7+pqFlmgqO4ZUfhvRFrCsXqUhkpsSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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