SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '860266b06b7173b72dc708ada084f1d31e99f2865fe7352d1e5f9f10166cc617' 
  AND token = 'acdPe8o/+tpRxdUHZv8ozhMNLJcrp6FwrSQ64Gt3ics=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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