SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '722a2dd8d14e12a48f19e9ddb999899567b55314e2509d6cd46b2828acc88934' 
  AND token = 'uZJckY9kuK1tfh8fCzXW/yNIejxUoVKV8tswK3kJTxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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