SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46c8104e28d5cac8a81a36b5c478497e2314e84fec5204889dc9422bf731baf3' 
  AND token = 'bGyxgVzPveROQgxzy76hFkYnXOs70zdpZ8/Do+o4Zvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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