SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cca7e1406271a6e680cd6d6b82992c0ff870921b9bdf353b40350c06ce033190' 
  AND token = 'zG2Ldpke+y4OUpNi9Kc00eXD0DZM7YwGe101IAfu/dg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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