SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7df1ae48975c6a18fa774bd4038ef0f5c26f5619cdda44ea2f88d2718bd1a11b' 
  AND token = 'FNdC6SK5D31fN8UlcdOGBC8rbQs8CqJzjb2wZuBoOQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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