Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df21eef420f61d6804010e1472d0562df4ad5f7f552f9eb4b682e9929c3e0368' 
  AND token = 'Z5am0rok0PlOhtPxsA1WFF3RrGT7JbCVc7IqqVVQcHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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