SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8c225e03da54056bfe935765892561fae6befc39df9790b13b3eef3242b6f418' 
  AND token = 'XAouIBq9kpYKbzVObVxgBsioRu/u0J08+tMUFKjnr2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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