SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5349483b01f3f544313c6585fe4f8308b37a7ff252b28a189d5b77ffba1da040' 
  AND token = 'bMhFm9WfR4RN8IUkV7HMYtWFae701gO7f8LlZ8N3zH8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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