SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '743ce320381a40edfc7f11565fb35630436e80184c977bc55ae7175c2c9e365e' 
  AND token = 'xv9zAXFmvAtX2dxmgGiZxJmuRCByG/dX5wqXlu5v2Zg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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