SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aaf93671ff0ff2563893533580ff4b3c3e50792a9203a732fff8677e40c6b49d' 
  AND token = '1l5kVcRAPnAiqvj+SyS6M0zkARjr1SJtJSREGTJNCr0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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