SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2d9cef0b8c36a71935ba43d04149a310e706b2773b10782224b84f3ed71456b' 
  AND token = '55MVXZNPvJ7JDCk/Mhl9m81GIJH0rPwXxqWuKgbu3s4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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