SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0209791654a46206936a72ce62fb027a0fc8adfbb65ab03de40dc8354f831f13' 
  AND token = 'nvWC/JuqNYiMgfuKg0owfgNNCG3n5EtFrzUUrupyXZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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