SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67d121b256b2b8d453ace8ff6ada0955bb8e8bc4ef67f6f97e64eef8678f5bf2' 
  AND token = '1XFJj+frDz8B6h3p2G3HLJaqM/7GAC8Fzjs8KrpWqrY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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