SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30b13d6ed7dc8faefdc5d60e7dc82dfc6c3b18927bc91cb1d6bf4ae1c4773cc0' 
  AND token = 'scwjlFQbtZh4fDXDagNyhUcLKY0S72FPykZG+UTuuII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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