SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd82c9c2fffe2c4ea47f8bfca4613f0ee06b1068d137a761f9fc6f9969b5e7a8e' 
  AND token = 'iFcBHww55YTJlJtAOS9uBFCiMr8XmWLJI+F/Bvb8fiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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