SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fa004081fd7067f8e21285d84da7bbb90bf9bae2ab3d0eac9ed5e64e20c5f25b' 
  AND token = 'nZkiIiADaV+w0xIBPQB7TyMf0mVMmDD8sOD2Gfvzsn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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