SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9b12dcecc42044d2395636ccb5fb94ffca199b6f46a497e0a290913ba18c7bbb' 
  AND token = 'PdmEH9x0rT9wLA8yJqLjyeC+W852QUiS/015Dt2iK+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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