SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed43e6d56d80f52afc5076b017e6ccbfe58e537fc963dbf8cfbbdbd1b1ac8559' 
  AND token = 'ZtRUuawl4EAph3htB6twFLQEGFlTgT33/JEasBkqDxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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