SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fa87008d65e6efa88623ea0f1881d5af0d2e0fcc7ad76b803a6533af442d9f9' 
  AND token = 'X9+HwdIRgCPjU8J+zZCFNteXkwsTwWLY9aHVrtooQtA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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