SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00b9b87b5b8698fe4f0770b9416fbff2f9b190da40d6465756b28390a8bcbec5' 
  AND token = '7jm9TiYLV6ug4wS6IvxTdV3U7hLvBAIKpurNo2T/gYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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