SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2885f9f2b72b5057f83f39febebec266fcbe56681cc493b916e80f3986277238' 
  AND token = 'eNx2em1qI6m3hpFgJF3ji/XBxZjtaKHiQdbJug7GLZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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