SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fdedc2503ee8e39ce6b005b118cadefd2c4b55af9e7cd975083d44ffc243dac' 
  AND token = 'IDFYFl9WLGEWcjFjImhb99WdpZiVFPg8Y1wj56EfIHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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