SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9f2a79d29f25f04c098e1b0ba550e587c0c96eb8f41952efe7dd8e34ad7432f3' 
  AND token = 'fjKaNk5Jg1taZKDHRhaXHZXslfIAZntdkIbsU2PlCq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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