SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3286cc59a5d3a127bbbde69deecce652ec4e7b836d47b8094ad0eb0af7d5b471' 
  AND token = 'Zve88pFon5IhSPtOV+4KPIG3/Few5MJ53Q3lzZqniOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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