SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '805caab874ba83b536958d9fa0714c947a24a844920d73f769d2a7e2683f7595' 
  AND token = 'zthZ/VvMXXKbUEdBqYf0uRdXJ/kmqnzA9KuafwD0lQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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