SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38229dbaf34c135876d9af02a433a6b8f8d6ab44d7446d99261a5066ec2a9efe' 
  AND token = 'iB4uSFL/yn9WCvvOVDLStR6WGPyzhVEmcvJTQtaixGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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