SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fe4962d1a31235a8b05deec35a70576d3efa0356088bdf2d66f006609957eaf' 
  AND token = 'RrVjxVh/V++XqeX4agf+0HN/RApGbgHrrEULWVF9vSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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