SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4223283321debbf1a78f459e94a24325802827a156b506ff62efc779f54e32cc' 
  AND token = 'TZIEW/gueckXUGGF3b34NBqC8RBIJ2Lg8PZH+Pj8S2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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