SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f7161be3c1a4b7f226548aba01a86e5e8883635d8cb69200ddc3792c55a88f2' 
  AND token = 'Z86RB2E9va9+VeG4liMqY9zlCyGuFOaaiYGWkLDQHu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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