SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7caa4e8b5c1339f1d294be08f0e2bddd7b75a25c1234dbe4f4383edbaf6e20ee' 
  AND token = 't1xSOJreFcVpjLJOPVSCHVNdmkwVEjjuUnRVwPSp6uk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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