SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '46b062f586bea969d1c7266ce152099aa622a6304b8d739448054407e4c71b3f' 
  AND token = 'WVNPgjzs+Zp0prEtz5M0eRyOge2h+Un4I/GHu7sdsH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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