SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dca55f3d98b220855fca1154909725d85fd49e6cefff85d8df6436789f3d3183' 
  AND token = '2KvFxZgqjC7pzKzlBL1aSvUg9PVOvSOW8Evs3GX2FEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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