SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdd8eeb83943db67b6df68e56a4f699df08715c9393063711b42108ba31aa933' 
  AND token = '2DAc/13ZVRq+fY7owcVF4hM7jqTmn+ZwuqmIhtepw4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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