SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d5b6a656a97ff49839fbb91df78911970920369a3ddbdaf4ab301464b8b2025' 
  AND token = 'UGs0/IXrYumbgQs+joInDqhuTQn4SzygERHHtKQ8G2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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