SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48afe5258f9e783d57223b301b1c8a75fca84be4fa31ad66769910fa578a81ea' 
  AND token = 'Gzgw61fxMiBhShrILSm9hlHMyAp40INmDjiNCTJvlA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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