SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8924c063170ec84b283e5a2c668799acbf51f1ae58dd650c2d0454f840b76b47' 
  AND token = 'oG3WH5Kwoij+hacVRUIRUhh159/DySqw36eG0lqzJwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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