SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '69f1810d8cbf518e6c03b25825455b91039727c8daa67d015efc2f6fda7aa3b9' 
  AND token = 'einNLzqyWQ9WEh52nI1XceaRopztJkWq0ejeEcy7myA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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