SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba8212231b637ba68a1a32875cefb3c069d408089b4f8c4db6e55ccdb5e7eee1' 
  AND token = 'QaRDhZ+km/rV+PznPIuynBrG9m3XPszy2/wHdFEkBig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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