SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e2b5be6388694ed9b7dc583535c5768bbe4b90af703c5d5186a6efd3cda1aaf' 
  AND token = 'KhzWBUvqTJtOYJP3PF0Rl1GSylzwurGqe0ZOe7hC/9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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