SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1bec2451bfdb4b725b9a4c49284a616d586add4993812bffbbfa1587b8d6f402' 
  AND token = 'O+o0dNwEkToKIGnkdfGsvNXOKavdGmihJlJBdedZkRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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