SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1c4830fe94e3ce359c47945592a014160348c45f152933dfe05b80682b6b64ac' 
  AND token = '5oGKJgHHvT7xHDb0vun6+4Zob8PZvjj5tjNVXEzgOe4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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