SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '749cf5e1179a19924bfe38e7981aab7eb95fa54fef016df363d881facf51b2a2' 
  AND token = '/ESnGgSnhw1bgEbt0Z47gUjwbRljHXJzlVciQHoLITQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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