SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2bd5d677e4dff15772c489b3008ca1516ab89f0b23ac348c08b5bef955ffd2e' 
  AND token = 'BuKSR+/VQKslPoEy1HUMyf+MkGMlSr+JwfV25NIvvDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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