SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9965b2150d3ab588ec643b8a1b8e471a78dd3e3e452841fb332630591aa9b419' 
  AND token = 'jlX6SfPUVgxiwvyhF8VPjN7hD8N1UDKzHCBmus5Ysd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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