SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de1bec156d941d946fa832d39dd4bbc2e73f91fca72cc45f54d4121025764e7d' 
  AND token = 'JQmBMHOI4tAP/UU/27MPivypjq0LI1CgS/d+gJUaK0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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